Credential for AWS
You must create a cross-account IAM role and register it as a credential in CDP prior to registering an environment. This is not optional.
Although credential creation can be performed as part of environment creation, we recommend that you create the IAM resources required for the credential and the credential itself prior to registering an environment. Typically, only AWS administrators can perform IAM resource creation on AWS.
For detailed instructions, refer to Creating a role-based credential.