I would like to know what force is moving the sun and moon in a circle above the earth? If "gravity doesn't exist" then what causes the sun follow the circular path that the flat earth model describes? I have not yet seen an explanation for this.
Since I haven't seen an answer from the flat earth side, I am going to venture my guess as to your question.
If this is wrong, hopefully someone from The Flat Earth Society will correct me.
I am just assuming, according to flat earth , that everything within and beneath the the dome (including the earth, the moon, the sun and the stars - there seems to be some disagreements amonst flat earth as to whether or not the planets exist - but let us just include them for the sake of ilustration) would be accelerating at the same rate of 9.8 meters per second per second since they are all contained within the confines of the dome and would continue to maintain their height above the earth, their spacing and their paths , et cetera, et cetera,and so forth, over the earth.
Just my guess, which admittedly could be all wrong, but just based on what I have read.