iPhone 6s won't stay long enough in DFU mode for me to update
My brother got my dad's phone locked and I thought of updating it through my Mac to get it unlocked. The problem is it won't stay in DFU mode for a long period of time for the update to finish. I've seen solutions online of holding down the OPTION KEY + CLICK UPDATE to specify which update file you'd like to install but I guess that only works for iTunes. I have a machine that runs Catalina. What can I do to get this locked iPhone updated?
iPhone 6s