Mi mix 2s failed to mount /firmware

Hello guys,b4 i write this i already google it but still not understand…just want to know n some explanations… 1.)i can’t mount firmware at ofox, cuz i lost qcn? Btw i forgot to backup my own qcn. 2.)How can i search my old imei n also lost baseband? can i get it back? 3.)Can i just restore from other polaris qcn n just random write will it work? 4.) can it fix my firmware mount/unmount issue? I also tried fastboot flash still can’t fix. thank you so much.

you need qpst to recovery qcn

Do u min , QFIl flashing right?EDL?