Just to clarify, it's my first time trying to unlock and root my phone, so I'm not very knowledgeable in this matter.
I basically followed the steps to unlock the bootloader.
Everything worked perfectly, I reached the recovery, went on 'apply update from ADB'.
But then, when I enter in cmd,
adb sideload 'whatever the filename
it prints out the Android Debug Bridge instructions on cmd rather than transferring the zip file to my phone, and the phone keeps on asking "now send the package you want to apply to the device with adb sideload filename ".
N.B.: the phone is recognized by adb, even when I enter adb devices, it is recognized.
Any help would be appreciated.