There’s no ‘Catholic bible’. There just the Bible.
There are two passages which refer to Confession of Sins.
Matthew 18:18
Christ says to Peter, whatcosver you bind on earth shall be bound in heaved, and whatsoever you shall loose on earth, shall be loosed on heaven.
As the priests are the successors of the Apostles, they also hold this authority.
John 20:21-23
‘As the Father hath sent me, I also send you. When he had said this, he breathed on them; and he said to them: Receive ye the Holy Ghost. Whose sins you shall forgive, they are forgiven them; and whose sins you shall retain, they are retained.’
This is why priests can hold confessions, and can absolve, by the Power of Christ in them.
Well I have Christ in me as do all believers but we do not claim that...only Christ does. I have been sent out by the authority of Christ as have all believers willing to do so...but we do not have the power to forgive sins against Christ nor to grant salvation...that is done thru Christ and by the power of His spirit...we simply give the message....as Paul stated...Christ crucified, dead and buried..rose from the dead...ascended where he sits at the right hand of God the Father.. We are witness to that.. not the one giving the forgiveness nor do we dare to think we have saved anyone...that is the work of Christ. I do not believe the catholic Priests hold any power whatsoever to forgive or absolve anyone. The priesthood was done away with at Calvary....completely and wholly fulfilled in Christ.