Witr prayer is one of the greatest acts of worship that draw one closer to Allah. It is the best prayer after the five obligatory prayers. It is a highly recommended Sunnah that a Muslim should observe regularly and not neglect. It was narrated that the Prophet (peace be upon him) said: “If anyone oversleeps and misses the witr, or forgets it, he should pray when he remembers.” (Authenticated by Al-Albani)
The majority of the scholars, including the Maliki, Shafi`i, Hanbali schools, are of the view that the minimum number of rak`ahs for witr is one rak`ah, because the Prophet (peace be upon him) said: “Witr is one rak`ah at the end of the night.” (Muslim)
In another hadith, the Prophet (peace be upon him) said: “The night prayers are two (rak`ahs) by two, but if one of you fears that dawn is about to break, let him pray one rak’ah to make what he has prayed odd-numbered.” (Agreed Upon)
For more information about the rulings of offering the witr prayer, you could watch this short talk with Dr. Muhammad Salah.
Source: Huda Youtube Channel.