Microsoft add new failover rights for Azure SQL Database to the December 2023 Product Terms. Now, when a secondary database replica is used only for disaster recovery, and doesn’t have any workloads running on it or applications connecting to it, you can save on licensing costs by designating the database as a standby replica. Microsoft provide you with the number of vCores licensed in the primary database at no extra charge, but you’re still billed for the compute and storage that the secondary database uses.

Find the announcement here: https://bit.ly/4b6kRKK, the relevant part of the Product Terms here: https://bit.ly/3Y6xsac, and instructions for configuring the standby replica here: https://bit.ly/3HxEzlc.