How to setup SSL enabled Atlas Cluster(For Mongo - 4.0 and Mongo 5.0), and where is the mongod.cfg file located to add the certificate details for Atlas clusters?

I would like to enable SSL on my Atlas cluster, and I looked through the below docs, however, may I know where is the mongod.cfg file located for Atlas Clusters, and what are the step by step procedure, to trust and enable SSL certificate in Cluster and the application client? Thank you!

Security — MongoDB Manual - Checked all the links under TSL/SSL section, still need help in SSL configuration.

Is this Atlas cluster or your own mongod installed on local host?
Atlas clusters have ssl/TLS enabled by default
What is your cluster type?
Paid or free
For Atlas cluster you can modify only some params from Atlas interface only
Provide more details on your cluster/setup

To reinforce this: MongoDB Atlas always requires TLS (SSL) network encryption over the wire: this is fully managed and configured for you so you don’t need to worry about it.

By the way TLS is basically the new/next-gen way of referring to what we all previously referred to as SSL