Den, this only needs to be posted one time/ one place, not four times.
It looks like the factory screwed that horizontal panel in-place. There are likely three or four evenly-spaced Philips wood screws placed near a horizontal edge, my guess is the top edge.
The factory used the fabric cover to conceal the screw heads. They peel back a pocked of that foam-backed fabric to exposed the wood, drive the screw to retain the panel, then use a soft broad blade to poke the fabric into the crack.
My suggestion is to start about an inch from the top corners, then start in the middle to expose the screws.
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