What's the compatible android versions?

Maybe your phone doesn't support your app because it doesn't have enough RAM. RAM isn't the phone's main memory, but a certain place on the disk, which is occupied by the program only during its operation and then freed after the exit from the program. If this program is too powerful, it requires a powerful phone, while your old model can no longer do the job. Of course, it could also be an old version of Android. How long ago did you update your operating system? If I were you, I would look into the app's compatibility with my android version. If you don't have enough memory, you can temporarily delete all files to work with such a heavy program and then make ANDROID DATA RECOVERY. I'd do exactly like that.