What is the grade of the following narration: "An illegitimate child does not enter paradise"? Is it a Hadeeth ? If yes, is it authentic?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.

This Hadeeth is unauthentic and it was even judged as Mawdhoo' (i.e. fabricated) by many scholars, like Mullaa ‘Ali Al-Qaari, Al-‘Ajlooni and Al-Fayrooz ’Abaadi .