It is incredibly easy to debunk flat earth. You can do it yourself in many ways. When you bring these up, flat earthers will simply ignore these and say there is no curvature when you can, if you wished to, even go out with a surveyor and measure it yourself.

And no, there is no conspiracy in Antarctica. There is literally zero supporting evidence for any such claims, and anyone can go to Antarctica if they wish. Literally, you need a permit for less than 2% of the areas in the entirety of Antarctica. It's expensive to go because it's quite far and there are a lot of risks and precautions anyone who takes visitors to Antarctica has to plan for to keep people safe.

Please actually do research. If you get into it, you will be able to point out and rebut all of their half truths and lies. Research every single claim they make, as they are mostly just based on repeating what the previous people have said and not doing actual research.

If you read my posts, I will be giving easy, common sense ways you can disprove the earth is flat on your own. And don't fall into the NASA trap. You can prove the shape of the earth without any NASA evidence whatsoever. That's a rabbit hole that no one will prove either way. But you CAN know the shape of the earth, and disprove it's flat quite easily and not need one speck of evidence from NASA.