And he “breathed on them and said to them, ‘receive the holy Spirit. Whose sins you forgive are forgiven them, and whose sins you retain are retained’” (John 20:22–23).
You will note the forgiveness of sins below.
Peter did not say, I forgive you and tell them to go say 10 rosaries. Nor did he do so in Acts 2.
When a person is forgiven....they're forgiven.
17“And now, brethren, I know that you acted in ignorance, just as your rulers did also. 18“But the things which God announced beforehand by the mouth of all the prophets, that His Christ would suffer, He has thus fulfilled.
19“Therefore repent and return, so that your sins may be wiped away,
in order that times of refreshing may come from the presence of the Lord; 20and that He may send Jesus, the Christ appointed for you, 21whom heaven must receive until the period of restoration of all things about which God spoke by the mouth of His holy prophets from ancient time. Acts 3:17-21 NASB