I wanted to test my app on samsung s10 I made my apk, this is the result of the release it seems to me ok:

Qt Code: 
  1. Verification succesful
  2. Signed
  3. Verifies
  4. Verified using v1 scheme (JAR signing): true
  5. Verified using v2 scheme (APK Signature Scheme v2): true
  6. Number of signers: 1
  7. Android package built successfully in 38.390 ms.
  8.   -- File: D:/GoogleDrive/c++/QT/build-ClientAndroidPaolo-Android_for_x86_Clang_Qt_5_12_2_for_Android_x86-Release/android-build//build/outputs/apk/release/android-build-release-signed.apk
  9. Warning: QML import could not be resolved in any of the import paths: io.qt.Backend
  10. Warning: QML import could not be resolved in any of the import paths: QtQuick.Controls.impl
  11. Warning: QML import could not be resolved in any of the import paths: QtQuick.Controls.Fusion.impl
  12. Warning: QML import could not be resolved in any of the import paths: QtQuick.Controls.Imagine.impl
  13. Warning: QML import could not be resolved in any of the import paths: QtQuick.Controls.Material.impl
  14. Warning: QML import could not be resolved in any of the import paths: QtQuick.Controls.Universal.impl
  15. Warning: QML import could not be resolved in any of the import paths: QtQuick.Extras.Private.CppUtils
  16. Warning: QML import could not be resolved in any of the import paths: QtQuick.Extras.Private.CppUtils
  17. 08:32:04: The process "C:\Qt\5.12.2\android_x86\bin\androiddeployqt.exe" exited normally.
  18. 08:32:04: Elapsed time: 00:40.
To copy to clipboard, switch view to plain text mode 

this is my manifest:
Qt Code: 
  1. <?xml version="1.0"?>
  2. <manifest package="org.nio74.clientAndroidPaolo" xmlns:android="http://schemas.android.com/apk/res/android" android:versionName="Versione1" android:versionCode="1" android:installLocation="auto">
  3.     <uses-sdk android:minSdkVersion="16" android:targetSdkVersion="28"/>
  4.  
  5.     <!-- The following comment will be replaced upon deployment with default permissions based on the dependencies of the application.
  6.          Remove the comment if you do not require these default permissions. -->
  7.     <!-- %%INSERT_PERMISSIONS -->
  8.  
  9.     <!-- The following comment will be replaced upon deployment with default features based on the dependencies of the application.
  10.          Remove the comment if you do not require these default features. -->
  11.     <!-- %%INSERT_FEATURES -->
  12.  
  13.     <supports-screens android:largeScreens="true" android:normalScreens="true" android:anyDensity="true" android:smallScreens="true"/>
  14.  
  15.     <application android:hardwareAccelerated="true" android:name="org.qtproject.qt5.android.bindings.QtApplication" android:label="ClientAndroidPaolo" android:icon="@drawable/icon">
  16.         <activity android:configChanges="orientation|uiMode|screenLayout|screenSize|smallestScreenSize|layoutDirection|locale|fontScale|keyboard|keyboardHidden|navigation|mcc|mnc|density" android:name="org.qtproject.qt5.android.bindings.QtActivity" android:label="Gold" android:screenOrientation="unspecified" android:launchMode="singleTop">
  17.             <intent-filter>
  18.                 <action android:name="android.intent.action.MAIN"/>
  19.                 <category android:name="android.intent.category.LAUNCHER"/>
  20.             </intent-filter>
  21.  
  22.             <!-- Application arguments -->
  23.             <!-- meta-data android:name="android.app.arguments" android:value="arg1 arg2 arg3"/ -->
  24.             <!-- Application arguments -->
  25.  
  26.             <meta-data android:name="android.app.lib_name" android:value="ClientAndroidPaolo"/>
  27.             <meta-data android:name="android.app.qt_sources_resource_id" android:resource="@array/qt_sources"/>
  28.             <meta-data android:name="android.app.repository" android:value="default"/>
  29.             <meta-data android:name="android.app.qt_libs_resource_id" android:resource="@array/qt_libs"/>
  30.             <meta-data android:name="android.app.bundled_libs_resource_id" android:resource="@array/bundled_libs"/>
  31.             <!-- Deploy Qt libs as part of package -->
  32.             <meta-data android:name="android.app.bundle_local_qt_libs" android:value="-- %%BUNDLE_LOCAL_QT_LIBS%% --"/>
  33.             <meta-data android:name="android.app.bundled_in_lib_resource_id" android:resource="@array/bundled_in_lib"/>
  34.             <meta-data android:name="android.app.bundled_in_assets_resource_id" android:resource="@array/bundled_in_assets"/>
  35.             <!-- Run with local libs -->
  36.             <meta-data android:name="android.app.use_local_qt_libs" android:value="-- %%USE_LOCAL_QT_LIBS%% --"/>
  37.             <meta-data android:name="android.app.libs_prefix" android:value="/data/local/tmp/qt/"/>
  38.             <meta-data android:name="android.app.load_local_libs" android:value="-- %%INSERT_LOCAL_LIBS%% --"/>
  39.             <meta-data android:name="android.app.load_local_jars" android:value="-- %%INSERT_LOCAL_JARS%% --"/>
  40.             <meta-data android:name="android.app.static_init_classes" android:value="-- %%INSERT_INIT_CLASSES%% --"/>
  41.             <!-- Used to specify custom system library path to run with local system libs -->
  42.             <!-- <meta-data android:name="android.app.system_libs_prefix" android:value="/system/lib/"/> -->
  43.             <!--  Messages maps -->
  44.             <meta-data android:value="@string/ministro_not_found_msg" android:name="android.app.ministro_not_found_msg"/>
  45.             <meta-data android:value="@string/ministro_needed_msg" android:name="android.app.ministro_needed_msg"/>
  46.             <meta-data android:value="@string/fatal_error_msg" android:name="android.app.fatal_error_msg"/>
  47.             <meta-data android:value="@string/unsupported_android_version" android:name="android.app.unsupported_android_version"/>
  48.             <!--  Messages maps -->
  49.  
  50.             <!-- Splash screen -->
  51.             <!-- meta-data android:name="android.app.splash_screen_drawable" android:resource="@drawable/logo"/ -->
  52.             <!-- meta-data android:name="android.app.splash_screen_sticky" android:value="true"/ -->
  53.             <!-- Splash screen -->
  54.  
  55.             <!-- Background running -->
  56.             <!-- Warning: changing this value to true may cause unexpected crashes if the
  57.                           application still try to draw after
  58.                           "applicationStateChanged(Qt::ApplicationSuspended)"
  59.                           signal is sent! -->
  60.             <meta-data android:name="android.app.background_running" android:value="false"/>
  61.             <!-- Background running -->
  62.  
  63.             <!-- auto screen scale factor -->
  64.             <meta-data android:name="android.app.auto_screen_scale_factor" android:value="false"/>
  65.             <!-- auto screen scale factor -->
  66.  
  67.             <!-- extract android style -->
  68.             <!-- available android:values :
  69.                 * default - In most cases this will be the same as "full", but it can also be something else if needed, e.g., for compatibility reasons
  70.                 * full - useful QWidget & Quick Controls 1 apps
  71.                 * minimal - useful for Quick Controls 2 apps, it is much faster than "full"
  72.                 * none - useful for apps that don't use any of the above Qt modules
  73.                 -->
  74.             <meta-data android:name="android.app.extract_android_style" android:value="default"/>
  75.             <!-- extract android style -->
  76.     </activity>
  77.  
  78.     <!-- For adding service(s) please check: https://wiki.qt.io/AndroidServices -->
  79.  
  80.     </application>
  81.  
  82.  
  83.  
  84. </manifest>
To copy to clipboard, switch view to plain text mode 

But when I go to install it on my device it doesn't install, I tried with other APKs downloaded from the web and it works but with my no:
Cattura.JPG

where am I wrong?