We all know that we must say the Act of Contrition (with sincerity and repentance).
It isn’t a rule that the priest must tell us to say it. We have been instructed of its requirement in our preparation for the Sacrament.
Some priests might justly assume, that knowing what we must say an Act of Contrition as an integral part of Confession, we say it without his always having to coach us to do so.
God’s kind blessings to you, Cecil.
livoniastmichael.org/Prayers/Form%20for%20Confession.html
As you see in this link, it is you who initiate the Act of Contrition. Certainly some priests helpfully do invite you to. Once again, note that the onus is on us as the penitent to say the Act of Contrition.
wordiq.com/definition/Confession