The process for connecting to a read replica is the same as connecting to the primary DB instance. You first need to get the endpoint. For every read replica that you create, it also gets a DNS CNAME, which is called an endpoint.
To get the endpoint for the read replica mywebappprdrr01, you use a cmdlet that we have used previously.
PS C:\> (Get-RDSDBInstance -DBInstanceIdentifier "mywebappprdrr01").endpoint
Once you have the endpoint, hop on to the bastion server, then from there, connect using MySQL client, as follows:
# mysql -u rdsdba -prdsdba123 -h mywebappprdrr01.cwrq5w1v98ur.us-east-1.rds.amazonaws.com --ssl-ca=rds-combined-ca-bundle.pem --ssl-verify-server-cert
In this example, we used the SSL connection method to connect to the read replica. To connect without SSL, just remove ssl-ca and ssl-verify-server-cert from the command...