In YouTube comments, you'll often see replies to genuine comments from somebody with the same profile picture as the creator. This is not them, it's a scam. If you contact these people on WhatsApp, they'll try to get money out of you. I thought it was pretty obvious, but apparently not.
Click the 3 dots next to the comment, then click report for scams, impersonations, whatever. Or even respond to the comment to make sure that others know that it's a scam.
This doesn't just happen on Kurt's videos, it happens on most big creators, and YouTube are doing very little to combat it.
Don't get scammed, do not message them. It is not, and never will be your favourite creator giving their WhatsApp number out in the comment section.