A text apology is a start. The one you say out loud, in your own voice, is the one that usually counts.

Typing an apology lets you edit yourself, which is exactly what makes it lighter. Saying it out loud puts you in the room with their reaction, with no way to delete a sentence halfway through, and that risk is most of what makes it land. They hear that you were willing to be uncomfortable for them.

Send the message if that is what gets you started, then follow it in person or on the phone. Lead with what you did and skip the reasons. If your voice shakes, let it shake.