If your USB Port of the phone just broke off or is otherwise not working anymore, you could

install Magisk to root and then use Flashify or FlashFire to install your Recovery.
Then do a backup (do at least backup your EFS partition because if it breaks, then your IMEI is lost and you aren’t able to connect to your cellphone provider anymore.)
Now use your recovery app to install your favorite ROM.
This way you’re able to still upgrade your ROM with a broken USB connection port