Android Question Different device Id on same device

Hi

Can anyone help
Why am I getting different device Id on same device from 2 different apps (each with different signature key)?

I need to get same ID.
Or alternatively any other element to identify they are on same device - can be imei, phone number, ip, Mac etc
I gone care if this element changes but for the same time it must be the same value
Even sharing data in common file will do so the data is stored in a file one app writes and the other can read

Must be sdk 31 as the apps need to be in Google store, so this is another thing - permissions that Google store allows

Thanks