I've watched a few videos of Thinking Crypto and sunny decree. But it seems that sunny has hidden the other uploads that he made. I don't know what's the reason for it. Why are you looking for them? Are you going to partner them with your project to have you advertise on their channel?
I'll give you a tip, just type the keyword crypto and you're going to see a bunch of crypto YouTubers that you may contact. It's easy to have them contact because their details are on their description.