What is the method of repentance and returning rights, or seeking absolution from a fasting person to whom an obscene and illicit message was sent during the day in Ramadan, from an unknown source, and then the sender repented?

A person must offer sincere repentance by abandoning the sin, regretting it, and resolving not to return to it. It is not obligatory for him to seek forgiveness from the one to whom he sent the speech; rather, his repentance between him and Allah is sufficient. He should also think well of his Lord, increase in good deeds that expiate sins, strive in inviting to Allah with wisdom and good counsel, and disseminate beneficial posts instead of what he used to send that was impermissible.