Follow the procedure below to convert a Synchronous standby instance to Asynchronous.
In the [Instances] tab, select the master instance of the relevant cluster.
Click 
.
In the [Streaming replication] section, edit the value for [Synchronous standby names].
Remove the "Application name" of the standby instance you want to be in Asynchronous mode.
Click 
.
Select the master instance and click 
.
Select the standby instance. [Instance type] will now show the updated status.
See
To learn more about the differences between synchronous and asynchronous standby modes and their behavior, refer to "Streaming Replication" in "High Availability, Load Balancing, and Replication" in the PostgreSQL Documentation.
