Lauch another game

Is it possible to do in GDevelop so that by pressing a button, another game is launched, installed on the user’s android phone? Help, please! This is very important and I really need it!

Tell me how this is going to happen if the other game is not installed on the device?

Just nothing will happen

Consider this reading Android Intents with Chrome - Chrome Developers
You need to find a way to put that link into GDevelop and create a button to call the link.

Something like this in a sub event with Javascript code
<a href="intent://scan/#Intent;scheme=zxing;;end"> Take a QR code </a>