SSL/TLS encryption without

AWS RDS Postgresql 12.11

sides=> select * from pg_stat_ssl where pid = 362;
-[ RECORD 1 ]-+----------------------------
pid           | 362
ssl           | t
version       | TLSv1.2
cipher        | ECDHE-RSA-AES256-GCM-SHA384
bits          | 256
compression   | f
client_dn     |
client_serial |
issuer_dn     |

I've got 85 connections where ssl='t'. How can connections be encrypted
using SSL/TLS without a client certificate?

--
Angular momentum makes the world go 'round.