Backup and restore is out. It simply doesn't work. The Azure systems are constantly being upgraded and backups from there generally can't be restored down to on-premises. It's similar to how you can't restore to 2017 from a 2019 backup.
So, you have a bunch of options within Azure to have readable secondaries and failover groups. I'd start there personally. Microsoft is working on a thing called Managed Instance Link, which will allow for an availability group between MI & on-premises, but it's currently one way only, from on-premises to MI. Further, it doesn't yet support going back the other way in the event of a failover. You'd be stuck up in MI. They also have replication set up, but I'd hate to rely on it. Replication is fragile on a good day, on-premises. Add in cloud connectivity and I'm guessing it's a ton of work to maintain. Better to use the cloud-based solutions I linked to at the start.