Ends a suppression, so the sender reaches the subscriber again. The record stays, with the ending noted on it, because the history of what was stopped and when is what answers a complaint or a carrier audit later. **Only reason `manual` can be ended here.** A `keyword_stop` is the subscriber's own statement and is never removable through the API: it ends when they text a start keyword to that sender, and nothing else. A `carrier_opted_out` mirrors what the carrier reported, so it ends when the carrier says so. Either returns `422`. Ending a suppression resumes messaging to someone your own records say did not want it, so do it only when you know why the `manual` record exists. An ID that does not exist in the workspace returns `404`, and one that has already ended returns `204`.