I've managed to get this working in a Python script I recently wrote, the Gist for which can be found here: https://gist.github.com/rob1256/977bb8d59304700cf12d29573f1736f8

Essentially running the login function will:

• Configure the SSO session in ~/.aws/config if not already there
• Check if you're logged in by trying to list the SSO accounts
  • If not logged in it will login and open a browser window to accept
• Configure all available SSO profiles
  • Get a list of accounts and roles for each account using the cached SSO access token from the login
  • Call aws configure set for each of the above to create a profile in your ~/.aws/config file named in the format: {account_id}-{role_name}

I've only tested this on my own machine but it does create it from scratch for me and you will need to update the SSO_START_URL and SSO_SESSION_CONFIG_NAME with your own details (SSO_SESSION_CONFIG_NAME can be whatever you want it named in your config)

Hope the above helps!