As long as it works on a degoogled Android phone I'm fine with it. Maybe someone in the supported countries with an GraphenOS or /e/OS phone can confirm?
Edit: for some banks it will just forward to the bank's app. So most likely it works as long as your bank supports degoogled Android, similar to how iDEAL + Tikkie works on degoogled Android with most Dutch banks.
I should've been clearer - by Google-approved, I meant that your device has to pass Google's remote attestation scheme. From https://support.wero-wallet.eu/hc/en-us/articles/25599098295...:
> I’m seeing this error message: "Your device does not meet our security requirements".
> /../ If the operating system is an Android variant (also called a 'custom ROM'), such as LineageOS or Pixel Experience, then the wero app can’t be installed for security reasons.