Ideally, when a user creates an account on your website, you will validate their email address by having them respond to an activation email that is sent from your website when the user registers. If, for some reason, you allow users to create accounts on your website before they have validated their email address, you can set the require_validation parameter conditionally in the SSO payload. If the user has validated their email address, set require_validation to false, or just leave out the parameter from the payload. If the user has not validated their email address on your website, set the require_activation parameter to true so that they’ll be sent an activation email from Discourse.