Make room for the other version
Ask what the other person understood before assuming that you are arguing about the same facts. For a message about how to apologize for sharing a photo without permission, use this factual base: name the exact action, the inconvenience it caused, and what you understand now.
Correct the record precisely
Correct only what you can support, acknowledge any real impact, and propose a practical way to prevent repetition. Offer the smallest useful repair and give a realistic time for completing it. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Agree on a testable next step
Do not inflate the apology, fish for reassurance, or demand immediate forgiveness. If the person has asked for no contact, repair what you can without sending another message. Do not recruit an audience, publish private evidence, or turn a misunderstanding into a campaign about character.