Qt application can not find xcb

Hello.
I’m trying to launch a Qt application.
This is the error that the application
qt.qpa.plugin: Could not find the Qt platform plugin “xcb” in “”
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

This’s snapcraft.yaml for app

name: managetime
version: "0.1.0"
summary: timer
description: |
    Application for time management
confinement: strict
architectures: [amd64]

apps:
    managetime:
        command: bin/run.sh $SNAP/bin/ProjectTimer
        plugs: [home, unity7, x11, opengl, pulseaudio, wayland]
          
parts:
    files:
        plugin: dump
        source: scripts
        source-type: local
        build-attributes: [keep-execstack]

    integration:
        plugin: nil
        stage-packages:
            - libc-bin
            - libclutter-1.0-0
            - libxkbcommon0
            - ttf-ubuntu-font-family
            - dmz-cursor-theme
            - libglib2.0-0
            - light-themes
            - shared-mime-info
            - libgdk-pixbuf2.0-0
            - libsqlite0
            - libsqlite3-0
            - libgl1-mesa-dev
            - qml-module-qtqml-models2
            - qml-module-qt-labs-folderlistmodel
            - qml-module-qtquick-xmllistmodel

In source: scripts has 2 catalogs. bin(run.sh, ProjectTimer) and Qt(plugins, libraries)

in script run.sh write paths where plugins, libraries.

  export LD_LIBRARY_PATH=$SNAP/Qt/5.11.0/gcc_64/lib:$LD_LIBRARY_PATH
  export QT_PLUGIN_PATH=$SNAP/Qt/5.11.0/gcc_64/plugins
  export QML2_IMPORT_PATH=$QML2_IMPORT_PATH:$SNAP/Qt/5.11.0/gcc_64/qml
  export QT_QPA_PLATFORM_PLUGIN_PATH=$SNAP/Qt/5.11.0/gcc_64/plugins/platforms/
  
  export QT_QPA_PLATFORM=xcb
  export QT_QPA_PLATFORMTHEME=appmenu-qt5

Tell me please, where can I have a mistake? All weekend try to find and fix this error.
Or maybe the snapcraft.yaml for the application is not compiled correctly? If anyone see, please correct.

Thx.

try using the desktop-qt5 remote-part and prepending your command with desktop-launch. The desktop-launch script handles all the setup for a standard Qt 5 project which uses the Qt packages from the Ubuntu repositories.

Please be sure that you have included at least desktop, x11 plugs in the plugs keyword.