Is this a scam? Someone wants to buy my GitHub handle for 1 million USD.

In short, a finance manager from a betting company reached out to me via my personal emails. He wants to purchase my GitHub handle for 1 million USD.

My GitHub username is just one character long, which is quite rare. However, I don’t believe it’s worth a million USD. Additionally, I suspect selling a username violates the TOS. Therefore, I don't want to take any risks and I love my username :)

I’m thoroughly confused about the GitHub support pages and couldn’t find any way to contact a real human. So, I’ve decided to seek help here.

My question is, has anyone encountered a scam like this before?