Meaning
The letters TM, written small and raised like a label, the trademark sign. It signals that a name, slogan or logo is being claimed as a brand, registered or not.
Online it has a well-known joking use: adding it to a phrase to make it sound like an official product or a signature move: “My famous Five-Minute Nap™️ strikes again” It works for personal mottos and inside jokes. For an officially registered brand, the proper sign is ®️.