Anthony can't get his computer to read his OnePlus 8 mobile phone. He plugs it in and there's no popup asking him if he wants to read it as a drive or a camera. Leo says to go into the USB settings and look for a mass storage mode. Choose it. Then it should show up as a hard drive. It may also be referred to as USB Transfer Mode.
The cable he's using may not have a data connection. It could just be for power. So if he can get a USB-C data cable, the popup should happen.