If you want to use multiple aws accounts over one sso login, the local setup looks like this:
Configure sso sessions using the --profile flag to generate a profile associated with the session:
aws configure sso --profile MyProfile-ProdCreate a session and give it a locally unique name (e.g. 'prod').
Add your sso url (e.g. 'https://megakuul.awsapps.com/start').
Now you can repeat this step for every account you want to use.
List your profiles with aws configure list-profiles.
You can set the AWS_PROFILE environment variable to set a default profile.
Finally, you can use aws sso login to authenticate against the provider and access all of your profiles.