iphone 7+ that has a smashed screen

I have an iphone 7+ with a smashed screen. I have tried to connect it to our computer to back it up, but the phone doesn't trust the computer due to factory reset and I cannot enter the passcode on the phone correctly because of the screen. Now the phone is disabled due to too many attempts and is suggesting to connect to itunes. Which I do, but nothing happens. I have also accessed the phone through the folder from the computer and there is no files