If the imam forgets to recite al-Fatihah in a secret prayer in one of the rak'ahs, what is required of him?

Question:
He says: Honorable Shaykh, may Allah grant you success, if the imam forgets to recite al-Fatihah in a secret prayer in one of the rak'ahs, what does he do if he remembers before the end of the prayer? And how does he inform the ma'mum? Because if he performs a rak'ah, the ma'mum will think that he has added another rak'ah.

Answer:
No, absolutely not. He must stand up and perform a rak'ah in place of the rak'ah in which he left out al-Fatihah. The ma'mum are required to follow him if they recite the tashahhud for him and he does not return and continues. This is evidence that he has left something out, so they follow him. Yes.