I put together a gregorian Confiteor, to be used at the Ordinary Form of the Roman Rite. I looked at the Liber Usualis, pp. 110-111, and I listened to this video from St. Ambrose's basilica in Milan, Italy (OF, for the confession):I also had a look at this video , showing the Confiteor from the Extraordinary Form of the Roman Rite (for the absolution):I made up the invitation myself.