I am trying to migrate on prem MYSQL to Postgres SQL on RDS instance but endpoint connection is failed

"FATAL: no pg_hba.conf entry for host" errors indicate that there was a failed authentication attempt to the database, so the connection couldn't be established. This can happen because of different reasons:

1. The authentication failed because the user/password credentials were invalid: ((user "xxxx", database "yyyy")). This could happen if you're trying to connect to the database using wrong or revoked credentials.

2. The authentication failed because the connection didn't use SSL encryption: (SSL off). If your client is not using SSL to connect to your database, you would see these errors even if you're using the right credentials to connect to it.

3. The authentication failed because the client environment had previously been configured for certificate-based Postgres authentication (mTLS) but the current server is not configured for certificate-based authentication. Look for a .postgresql subdirectory in your current user HOME directory and remove or rename any postgresql.crt subdirectory in there.

Looks like your client is not using SSL to connect to the database.