“All good” Can Mean “No Problem”

In everyday Australian conversation, all good often accepts an apology or signals that a small problem has been resolved. It is close to “no problem”, “don’t worry” or “that’s sorted”, rather than a serious claim that everything in the world is excellent.

“Sorry I’m late.” “All good. We haven’t ordered yet.” The reply removes the other person’s concern. It can also confirm that a task is complete: “Is the booking sorted?” “Yep, all good.” The phrase is relaxed and conversational. In a formal email, a specific statement such as “The booking has been confirmed” is clearer.

https://dictionary.cambridge.org/dictionary/english/all-good