For B2B and team-based products, this endpoint sends an invitation to a given email address to join a team. The user's accept membership route POST /u/memberships/{:id}/accept is used to confirm membership creation.

For B2C products, the user must authorize membership creation using the POST /u/memberships route. The endpoint returns a membership creation token which must be passed into this route which confirms membership creation with data and scopes.

This route may also be used to invite members to B2C products. Pass in the email without a team ID to do so.