The browser login of my bank needs a separate application that's windows only or an app. The Java(!) application Jameica saved my ass for the 6 years I'm on Linux now. It can manage multiple accounts. It offers statistics, saves all the transfers, deposits and balances ad infinitum on your disk, is searchable and has templates and schedules for transfers.
The protocol my bank uses is FinTS, I think. I'm logging in via a certificate file and a password.
I don't want to use an app, cause I trust my cutting edge Linux (Kernel 6.7.6) a lot more than my possibly malicious app riddled outdated android.