Question abouth ssl_ciphers Amazon RDS postgres

I'm doing some experiments with AWS RDS Postgres and examining the ssl, rds.force_ssl and ssl_ciphers parameters of the RDS.

If I set the ssl and rds.force_ssl to true, then I would like to set the ssl_ciphers parameter too, but I see that the parameter is not modifiable.

The default ssl_ciphers value is "HIGH:!aNULL:!3DES" for postgres version 13.

Is there another way to get around this value or am I stuck with the default value?

Thanks in advance.

Regards

Marian