Start with the RTO and RPO of the databases. This will guide you on the backup scenario you need. Having the databases in an AG makes no difference to what you need to do re backups.
An AG can make a difference regarding which node the backups run on. If you have licenced only a single node you have to run the backups on the primary node. If you have licences for two nodes you can run the backups on either the primary node or one of the secondary nodes.
You will need to set up your backup jobs on all nodes, and work out how to enable and disable running the jobs during failover. Alternatively if you are on SQL2022 you could use a Contained AG and put the jobs in the AG instance of msdb.
Original author: https://github.com/SQL-FineBuild/Common/wiki/ 1-click install and best practice configuration of SQL Server 2019, 2017 2016, 2014, 2012, 2008 R2, 2008 and 2005.
When I give food to the poor they call me a saint. When I ask why they are poor they call me a communist - Archbishop Hélder Câmara