how to configure AWS Config to block non-FIPS endpoint for a particular account

Hi There

AWS Config is a service that helps you assess, audit, and evaluate the configurations and relationships of your resources. You can use rules evaluate the configuration settings of your AWS resources. It will not help you block access to specific endpoints.

One way you could achieve this is to use AWS Route53 DNS Firewall to block all non-FIPS endpoints.

See https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/resolver-dns-firewall-overview.html