"role" for read-only database

I use AWS Aurora rds service for postgresql.

Aurora has 2 DB instances (host addresses) for the same db; 1 for RW and 1 RO.

In Vault I create role&connection for RW instance and don’t have any issues. I use dynamic credentials config.

The RO DB Instance doesn’t let Vault’s use “creation_statements” because of its nature.

/ $ vault read database/creds/backend-finance-readonly
Error reading database/creds/backend-finance-readonly: Error making API request.

URL: GET      
Code: 500. Errors:

* 1 error occurred:
        * failed to execute query: ERROR: cannot execute CREATE ROLE in a read-only transaction (SQLSTATE 25006)

/ $

How can I use dynamically created credentials by RW connection with RO Instance connection?

Thanks & Regards