Instructions for re-installing Google Authenticator without loosing any current authenticator items.
After the re-install is complete you will be good to go and the Authenticator app will once-again open without crashing. You may want to re-install the app over WiFi as it will re-download the app from iCloud / Apple store.
Honestly, Google authenticator is behind-the-times in terms of a solid 2-factor authentication app. You can tell by the many 2-star and worse reviews. Personally, I’m switching to Authy after this IOS 14 mishap