Take out the installed app package from the Android phone and export the apk

Export steps:
1) Find the package name of the application
and execute the command:

$ package:com.android.internal.systemui.navbar.threebutton

输出结果：
package:com.google.android.apps.work.oobconfig
package:us.zoom.videomeetings
package:com.qti.qualcomm.datastatusnotification
package:android
package:com.android.hotwordenrollment.xgoogle
package:com.google.android.pixel.setupwizard
package:com.android.theme.icon_pack.rounded.launcher
package:com.google.android.imaging.easel.service
package:com.android.egg
package:com.android.mtp
package:com.android.nfc
package:com.android.ons
package:com.android.stk
package:com.android.backupconfirm
package:com.instagram.android
package:io.appium.android.apis
package:com.lpstu.max.junk.clean
package:com.android.theme.font.arvolato
package:com.google.android.deskclock
package:com.android.internal.systemui.navbar.twobutton
package:org.codeaurora.ims
package:com.android.statementservice
package:com.google.android.as
package:com.google.android.gmadb shell pm list package

or:

Find the package name of the currently running APP

adb shell dumpsys window | findstr mCurrentFocus

2) Find the location of the application backup package, for example, find com.lpstu.max.junk.clean
and execute the command:

adb shell pm path com.lpstu.max.junk.clean
output:

package:/data/app/com.game.play.gogogo-1/base.apk
3) Extract the installation package
Execute the command:

$ adb pull /data/app/~~N5mcbfKvj_bFyub8Tpxk2w==/com.lpstu.max.junk.clean-PPGG2XCe2T12yCEA4R9B9A==/base.apk C:\hh The path to put on your computer

Results of the:

The extraction is successful, and it can be sent/copied to the mobile phone for installation.