Don't bother. It's not a "debate", at least not a scientific one. People who are flat Earthers in spite of the wealth of easily found and simple-to-understand evidence haven't based their belief on science, but on personal conviction. They will never trust anything that anyone says or writes. They will never accept photographic or video evidence. They won't even accept it if they're brought up into space and given a tour of the surface of the Earth from many different altitudes and given free rein to conduct experiments while on board. They'll say it's a set-up.
Once people have gone down this rabbit hole, there is nothing that will pull them back. The amount of trust you need to build with them will require a massive investment of time and energy that will never be justified by the pay-off, if it ever even comes.
At best, they'll think you're a sheep, or maybe a well-intentioned idiot. At worst, they'll say you're in on "it".
Their minds are made up now and forever. Just let it go. Your resources (time, intellectual and emotional energy, whatever) are better spent on trying to keep people from falling into the hole to begin with. There will always be some who reflexively and irrevocably disbelieve everyone with any sort of authority or officially acknowledged expertise, if only because science can never get anything exactly, 100%, perfectly right, because science is done by scientists, who are not omniscient beings. They will leap on any discrepancy or shortfall or mistake (or the dishonesty of a tiny minority of scientists who fabricate data outright) to justify this, and that will be enough to last them the rest of their lives.
The best thing scientists can do is to stop trying to debate them, especially in a public manner. It's never a debate; it's just providing a free platform for them to spew conspiratorial thinking. Stop writing articles like this while you're at it. Don't ever acknowledge the people who believe these things – just provide the evidence, don't engage them directly, and move on.