Can mortal sins be forgiven without confession and can one go to confession online
The Sacrament of Penance isn’t just a simple cry to God for mercy, it is also a celebration of the mercy of God and a journey with the penitent in his road to deeper conversion. Christ commands the Apostles to forgive sins, and retain as they deed fit. He also commanded them to spread his word, to baptize and bring men into his Church. Confession is reconciliation with God and the Church. The priest, who is a symbol of God’s mercy; an Image of Christ’s forgiving power acts in his stead and in the place of the Church to forgive and to bless, to encourage and to direct the penitent. He weighs their sins, speaks words of encouragement to those who’re despairing, and those who are lukewarm find an opportunity to be renewed.
Since we are all bound together in the Body of Christ, sin causes this body to suffer since one is “torn” away from it. Mortal sin estranges one from God and community, and the healing of this rift must begin in the heart of the penitent by way of Contrition, then Confession and end in restitution. When this is done, the penitent is reconciled to both God and his Church. The Catholic Church therefore teaches that contrition is a condition for receiving God’s forgiveness, and it precludes the intention to confess our sins when we have the opportunity. So if the penitent dies before actualizing this, their sins have been forgiven as long as they prayed for mercy. God has ordained this sacrament to bind us to himself, and also to one another. It is not possible therefore, for a mortal sin to be forgiven without confession.
Catholic Answers has this to add :
Sacramental confession is normatively required for the forgiveness of mortal sins; it is not absolutely required. What this means is that, in extraordinary circumstances, mortal sins can be forgiven outside of sacramental confession. If a Catholic is dying and cannot go to sacramental confession, his mortal sins may be forgiven if he repents with true contrition (i.e., sorrow for sin) and has at least the implicit intention to go to sacramental confession if the opportunity is made available.
Can one receive online? No, for one to receive this sacrament, they must be physically present with the minister who celebrates with them. It is not possible, at least at the moment, to receive any sacrament online, and judging by the nature of Sacraments, the Church can never begin administering sacraments online.