There are no opening credits. The title doesn't even appear on screen until the end.
The film's title card mimics the actual X rating card used by the MPAA.
After the credits, there is a trailer for the prequel "Pearl" starring Mia Goth, with the events taking place in 1918.
For North American Releases: A trailer/advertisement appears at the very end credits of X for possible upcoming feature film, Pearl in late 2022.