The easiest way to authenticate users in the widget is utilizing SSO Token.
SSO Token is a JWT token which includes user's external ID (ID in your product), name, email, title*, picture*, and bio*. (The ones with * are optional)
If user exists based on the external ID or email address, they will be automatically signed in. If user does not exist, Tribe will create a new user based on the information provided and will log them in.
To generate an SSO token you should go to Admin Panel and under Apps, install JWT SSO app. There, you'll find your SSO private key as well as instruction on how to generate the SSO token with sample codes in Node.js, PHP, Java, Python, and Ruby.
You should pass the SSO token in the query string. Here is how you can pass the SSO token to a sample widget: