What peripherals do i use when sending and recieving data with BluetoothLE?

I have a app which i've been testing. I want to send texts from my phone which runs on Android 8.1.0, and to and my teachers phone (a Note 20 ultra, i don't know what the version number is). Currently the way that i'm connecting with the device is by grabbing its specific address. Both addresses for both phones have been defined with strings, because right now i am only concerned with making sure that the devices can send and receive texts, not with whether or not it can find a device. If i have to change which device is recieving texts and which one is sending them, then i just swap the addresses.

When the app sends texts, it writes strings to the connected device, and the connected devices reads them. The UUIDs for the read and writeStrings blocks are "0000ffe0-0000-1000-8000-00805f9b34fb", for the characteristic and service UUIDs. I saw this in question posted from someone else on here, I can't find the question unfortunately.

When i test the app it says that the IDs are not assigned or not recognized (I dont remember exactly what the error said).

I know about the nRF connect app, but i don't know how to get the data from the nRF app to appinventer, so that i can put that information in my app.
Application file
the_app.aia (142.7 KB)