Is the story true about a priest who challenged a Muslim with 22 questions on religious concepts, and the Muslim answered them with satisfactory responses from the Quran and Sunnah, and then the Muslim asked about the key to Paradise, leading to the conversion of the priest and his companions to Islam?

The story mentioned has not been reported in any reliable source, and it bears signs of fabrication and وضع (forgery/concoction) due to its artificiality, weakness, and banality. Among these signs is the statement: "The four that have no fifth are: the Quran, the Gospel, the Torah, and the Psalms," which is incorrect. The Quran mentions the scriptures of Ibrahim and Musa, and there are other books that Allah revealed but did not mention to us. Also, the statement: "The grave that moved with its occupant is the whale when it swallowed Yunus (peace be upon him)" is false, because Yunus (peace be upon him) did not die in the belly of the whale for it to be called his grave.