Mrs replaced old Realme phone with a new one 12+ 5G I think it is, both Android 12. App worked fine on the old phone, will not open up on the new one, logo just goes round and round. She spent ages in a large branch who said it must be the phone or her internet, but everything else works OK. In the end one worker said it does not work with all new phones, this model has not been out long. Do they update this app regularly?

Delete the app on the phone  and fully reinstall. Or,

 

Check on Google Store if any pending updates. Or,

 

Reset phone.