How to use 2 sets of credentials for Snapshots?

I’m already taking snapshots to an S3-compatible data store, but I want to back up some other indices to a different location. All of the instructions for setting up snapshots say to store the credentials in s3.client.default.access_key and s3.client.default.secret_key.
What should I name the new set of credentials I want to use for the alternate location?

“Hidden” in the documentation it states that when you create the repository you can set the client field in the submission. The only catch is that you can use _ but not - in the client name.

So I was able to create s3.client.some_thing.access_key and s3.client.some_thing.secret_key and create the repository setting "client": "some_thing" .