Is it obligatory to inform the owner of the right about what was taken from him and ask for forgiveness, or is it sufficient to estimate the value and send it?

Among the conditions for sincere repentance (Tawbah Nasuh) is to return what is rightfully due to its owner, as long as one knows him. This is based on the Prophet, peace and blessings be upon him, saying: "The hand is responsible for what it took until it returns it," and because the lives, wealth, and honor of Muslims are sacred. If there has been an increase in wealth or a benefit gained, it must be returned along with the original amount. Let the Muslim hasten to return the right to its owner. If one fears exposure or causing a problem, then one should find a discreet way to deliver it, such as sending it via a bank transfer in the owner's name without mentioning one's own name.