Hi @Moonlight ,
>i have red we can backup and restore on the new replica then initiate the synchronization, please how can i go with this approach
Restore a recent database backup of the primary database and subsequent log backups onto the server instance that hosts the secondary replica, using RESTORE WITH NORECOVERY. Then you can choose the "Join only" option on the Select Initial Data Synchronization page when using the Add Replica to Availability Group Wizard.
For more details please refer to the following article.
https://www.mssqltips.com/sqlservertip/4598/add-secondary-replica-to-existing-sql-server-alwayson-availability-group/
Hot issues in October—Users always get connection timeout problem when using multi subnet AG via listener. Especially after failover to another subnet