iPhone 7plus can not update and turn on

it was work fine until I tried to updated it to ios13.6 then I don't know what happen.

the iPhone can't turn on and keep restart, then it on the recovery mode so I connect it to my MacBook which is on the latest version and click on update. every turn to be fine then it pop up "The iPhone “iPhone” could not be updated. An unknown error occurred (7)."

I have no idea what going, I tried so many time and it still say the same thing, so I gave up and hit on restore. however, it said same thing except change from updated to restored.