Should the supplication for completing the Quran in the Night Prayer and Witr be before or after bowing?

No specific supplication (du'a) has been authentically reported from the Prophet, peace be upon him, for the completion of the Quran. However, it is recommended to supplicate for the good of this world and the Hereafter upon completing the Quran, based on his saying, peace be upon him: "Recite the Quran and ask Allah by it before a people come who recite the Quran and ask people by it." And Anas ibn Malik, may Allah be pleased with him, whenever he completed the Quran, he would gather his family and supplicate with them. This supplication is not required in prayer except as part of the Witr prayer (either before or after the bowing).