Can’t acces storage when mounted with TWRP

I accidentally deleted the OS from my htc one m8, and I try to reinstall the original rom but I am stuck at connecting my phone to the pc. I boot into TWRP and mount but on pc all I see is the phone, some folders (TWRP folder) and that’s it. I can’t copy anything in the TWRP folder nor on the internal storage. Sometimes backup subfolder shows up but still can’t copy over the ROM,any ideas?With adb push I can only send over the zip (managed to do it 1 time) but can’t unzip it there.