Yeah, this one's a common point of confusion. No, you can't use USB for the initial setup if there's a label covering the port.
You have to set it up wirelessly first using the HP Smart app and an internet connection. After it's fully configured and on your Wi-Fi network, you can then print using a USB cable if you want. But even for USB printing later, the printer itself must stay connected to the internet.
If you're stuck: If HP Smart can't find the printer during wireless setup, the most likely culprit is the printer's setup mode timing out. Swipe down on the touchscreen, go to Network Setup > Restore Network Settings, confirm, wait a minute, and try the app again.