If your game was never linked to Facebook, Google, or Apple, and you lose your data, you cannot recover it manually. However, Rovio Support can often restore your account if you provide specific identifiers. Step 1: Find your Player ID
To help look into specific issues with your game file, let me know:
Angry Birds 2 utilizes a hybrid system to manage save files. It combines local device storage with cloud-based account syncing. Local Storage angry birds 2 save data
Log into your account. Your cloud save will now sync with your Google or Facebook profile. The Universal Method: Facebook Login
If save data is lost, the recovery process is mixed. If your game was never linked to Facebook,
Unfortunately, after deletion or factory reset. Your only hope is:
To make sure I give you the most accurate advice for your situation, let me know: It combines local device storage with cloud-based account
Ultimate Guide to Angry Birds 2 Save Data: Backup, Transfer, and Troubleshooting
Do this today. Keep it in your camera roll so you have it if the game crashes and refuses to open.