Repentance from theft – a condition for repentance for theft?

Hello Rabbi,
Is the mitzvah of Shabbat robbery a necessary condition for repenting for robbery, or is it a mitzvah that only requires that I have robbed someone before?
From an explanation, I would say that without the return of the decree, there would be no true repentance on the part of the robber, and in any case, there would be no answer.
But then the Sabbath commandment of stealing is not a necessary condition for repentance, but only a sign of insufficient repentance, and repentance is the necessary condition.
What do you think?