AWS CLI and a JSON file

I'm setting up my AWS CLI. To access to AWS services like EC2, I have to switch roles.

I used the command aws sts assume-role, and it spit out JSON with Credentials and AssumedRoleUser, complete with a session token. That's great!

Now what? I've googled around, but I cannot figure what to do with generated JSON.
How do I tell AWS CLI, "Use this JSON to authenticate with this role"?

Here is the (redacted) JSON I have:

{
    "Credentials": {
        "AccessKeyId": "XXXXXXXXXXW5YABBKUXQ",
        "SecretAccessKey": "XXXXXXXXXXXXXXXXXXXXB2EFEUmCtuwbJPcMBF02",
        "SessionToken": "XXXXXXXXXXsi6md6PTNHYjHUljav",
        "Expiration": "2021-12-03T04:59:02+00:00"
    },
    "AssumedRoleUser": {
        "AssumedRoleId": "XXXXXXXXXX:dev",
        "Arn": "arn:aws-us-gov:sts::999999999991:assumed-role/PROJADMIN/dev"
    }
}

The answer was to ignore everything in the JSON except the "SessionToken".
To use the session token, either add this to the credentials file profile with the same AWS keys, or export it as an env var

aws_session_token = XXXXXXXXXXXXXXXXXXXXXXXX

StackExchange DevOps Q#15066, answer score: 1