How the error looks like:
How to fix:
1. If you're on Windows, install 7zip & then open the .ipa with 7zip as archive. If you're on mac, rename it to .zip & then extract it by double clicking it.
2. Double click payload & double click the .app (on MacOS you need to right click .app & click "show package...")
3. Search for a file called "Info.plist" & double click it or drag it into a text editor.
4. Search for "UISupportedDevices" & something like this will popup:
5. Add your device from the Cydia Impactor error to the array.
So if it says "Device iPad5,4 not in SupportedDevices list' add it like this:
6. If you're on windows, save the file & install the .ipa, if you're on MacOS, go back to where the payload folder is located, select all files from there & compress it (make zip) & then rename it to .ipa instead.
However, sometimes the developers have a valid reason for not adding your device & the app won't work properly.