Quoted (with typoes fixed) from my 1yo answer on Reddit:
Unfortunately, if the app creator did not add their associated domains (see also Supporting Associated Domains) to the app and their website there is no way to get Bitwarden (on iOS) to recognize it within a password manager using auto-fill.
Best you can do is contact the app maker and send them those links and ask them to help password managers recognize their app by correctly implementing associated domains.
I have a number of apps, including my bank, that have this problem too 