Hi @rmendoza,
Welcome to the Auth0 Community!
Usually, you can accomplish this by using a Post Login Action flow. In the script, you can use the Management API to assign roles to your users.
Please see this related knowledge solution regarding this:
https://community.auth0.com/t/how-can-i-use-the-management-api-in-actions/64947
Now, you will want to make sure that you have these Salesforce roles created in your list of Roles before assigning them to users.
Lastly, if you were to use a refresh token to get a new access token, all of your action scripts will rerun and trigger again.
Keep me posted on how this goes for you.
Cheers,
Rueben