To what extent is the hadith "He who sleeps without having prayed Witr is not of my Ummah" authentic?

The hadith (definition) with the wording "Witr is obligatory" has not been found. Rather, what is known is the wording: "Witr is a duty (haqq), and whoever does not pray Witr is not one of us." Abu Hanifa used this hadith as evidence for the obligation of Witr prayer, while the majority of scholars held it to be recommendable, reconciling this hadith with other hadiths that negate the obligation of prayers other than the five prescribed ones, such as the hadith of Talhah ibn Ubaydullah and Mu'adh ibn Jabal, and the hadith of Ali ibn Abi Talib: "Witr is not compulsory like the prescribed prayers."