You can add a specific subscription to a contact. In Intercom, we have two different subscription types based on user consent - opt-out and opt-in:
1.Attaching a contact to an opt-out subscription type will opt that user out from receiving messages related to that subscription type.
2.Attaching a contact to an opt-in subscription type will opt that user in to receiving messages related to that subscription type.
This will return a subscription type model for the subscription type that was added to the contact.