Amazon S3 GovCloud is Amazon's Regions designed to host sensitive data, regulated workloads, and address the most stringent U.S. government security and compliance requirements.

In order to connect to it, you need to manually specify one of the addresses in the Server Endpoint field, depending on the configuration and region of your GovCloud:

https://s3.us-gov-east-1.amazonaws.com
https://s3-fips.us-gov-east-1.amazonaws.com
https://s3.dualstack.us-gov-east-1.amazonaws.com
https://s3-fips.dualstack.us-gov-east-1.amazonaws.com
https://s3.us-gov-west-1.amazonaws.com
https://s3-fips.us-gov-west-1.amazonaws.com
https://s3.dualstack.us-gov-west-1.amazonaws.com
https://s3-fips.dualstack.us-gov-west-1.amazonaws.com

For more details, we recommend you refer to Amazon's documentation at:

https://docs.aws.amazon.com/govcloud-us/latest/UserGuide/welcome.html