How can I stop auctioneer.50million.club window from popping up?

For almost 2 weeks now, a new window called auctioneer.50million.club keeps opening up. This constantly happens every time I'm on Safari. Whenever I click to type in on a website or open a new tab, this window pops up. It's a white screen and it says "status: invalid," I can close it but it's annoying since it constantly opens up. A few of the websites that mention how to remove it don't work, because I haven't installed anything from this website. They all mention to remove it from extensions, but I can't find it on there. Please help me.