Computer doesn't connect to iPhone hotspot?

So my friend has a laptop with the Windows 10 pro operating system and tries to connect it to the hotspot of his iPhone 8, his cell phone provider is tchibo. But unsuccessfully because the computer only ever writes that it can't connect to the network. Does anyone have any idea why?

Has he activated the hotspot function on the cell phone?

Maybe look in the hotspot settings if there's something on display.