Is it permissible to ask the intermediary about the financial donor?

There is no harm in identifying the doer of a good deed in order to thank him, pray for him, and reward him if possible, based on the hadith: "Whoever does you a favor, recompense him. If you do not find anything with which to recompense him, then supplicate for him until you think that you have recompensed him," and "He who does not thank the people does not thank Allah." If it is not possible to identify him, then pray for his well-being, based on the hadith: "Whoever has a favor done to him and says to the doer of it, 'May Allah reward you with goodness,' has indeed fully praised him."