Bring your tinfoil hat.
They say that there is no consensus at all, there are no studies on the health effects of genetically modified food, the ones that exist are terrible, that government and scientific bodies don't really mean it when they endorse the safety of GM foods, that Europe is also lying to the world, and a bunch of other stuff with dozens of footnotes.
Unfortunately, they are more like editorial support than references, with links to articles they like or dislike.
I clicked on the 93 signatories list and it said:
Which is the most accurate thing on their page.
But the part where you can click and add your own name works just fine. Maybe when they get to 93 signatures the link will go live again.
H/T Dr. Cami Ryan