See 259 . Besides there being absolutely zero Cath priests in the NT, Scripture teaches that the binding/loosing of sins pertains to judicial judgments, which the OT magisterium also engaged in. (Dt. 17:8-13) And which the often-invoked Mt. 18:15-17 pertains to, but the church corporate is to be involved, as seen applied in 1Co. 5, in which Paul leads the whole church in delivering a man to the devil for restorative chastisement. And latter exhorts the church to forgive the man, which action Paul concurs with as in the person of Christ. (2Cor. 5:7-11)
This binding is also declarative in Acts 5 and 8, resulting in Divine judgment or the threat thereof. In the latter case we see Peter telling Simon to pray himself that he be forgiven, while the latter asks prayer for him, which is met by silence in the narrative.
God can also have regard to the intercession of other believers for those being chastened for sin, likely including sins one is ignorant of, and which intercession primarily is to be expected of the presbuteros (senior/elder) office, as James 5:14,15 teaches.
However, besides judicial judgments, Mt. 18:18-20 and James 5:16-20 teach that spiritual binding and loosing also is provided for all believers of righteous faith as exampled by Elijah, who bound the heavens for 3.5 years and then loosed them (now there is a solution for sppsd Climate Change!).
And which calls for confession of faults to each other in general and communal prayer for them. And which ministry of all believers includes canceling a multitude of sin due to turning one to repentance.
So IOW, when someone confesses a fault to others, the others are not to hold it over their heads any more or not to hold it against them. (1 Corinthians 13 - Love keeps no record of wrongs)
It's to be loosed. Or the person is to be loosed from any further association with that sin.
Forgive as God has forgiven you in which He throws our sins into the sea of forgetfulness.