He says: If someone takes on a debt and does not intend to pay it back.

Then when he died, his wife paid it off for him.

Is it accepted from him? Yes, the debt has been settled.

Whether he intended to pay the debt or not, the debt is settled, the matter is finished. But he is sinful before Allah the Blessed and Exalted for his intention.

This corrupt intention—the debt is settled, that's it, he will not be held accountable for it on the Day of Judgment. If someone pays it off for him, he will not be held accountable for it on the Day of Judgment, but Allah will call him to account for his corrupt intention.

Which is that he did not want to return people's rights.

Their debts—Allah is the One whose help is sought.