Keep the app open in the background

[TIMAI2]

Read all of this, see if it will work for you:

Open Source • Background Tasks: Itoo

Itoo 4.4.2 Sky :octopus: Github Donate [BuildWithLove] [forthebadge] An efficiently designed virtual background execution environment for App Inventor. Powered by the ItooX framework. It allows you to run blocks in background the same way you do normally when the app is active. :star2: Please go through all the details and documentation listed below before you try to use the extension or seek help from others. Efforts have been made to be precise and simple at t…

or also consider this:

Ullis Roboter Seite/AI2 Keep Alive