To stop receiving engagements on a contact channel, you can delete the channel from a contact
Source:R/ssmcontacts_operations.R
ssmcontacts_delete_contact_channel.RdTo stop receiving engagements on a contact channel, you can delete the channel from a contact. Deleting the contact channel does not remove it from the contact's engagement plan, but the stage that includes the channel will be ignored. If you delete the only contact channel for a contact, you'll no longer be able to engage that contact during an incident.
See https://www.paws-r-sdk.com/docs/ssmcontacts_delete_contact_channel/ for full documentation.