Unfortunately, the photo is a bit bad.
Could it be that only a plastic cap was pressed into the hole here, thus “hiding” the screws. See if Dumdie can reel it out with a needle.
Otherwise, the case looks like the Ubook X. You don’t have to heat anything. The housing is only clipped.
If you can’t find any screws at the bottom, I would carefully start opening the case. I would start at the top. The housings are all constructed similarly. Here is a video H13, which is almost the same.
When you have reached the bottom, you will already notice whether there are still screws hidden.
And please do not try to loosen the screen glass with heat. The touch is glued to the display and on the back of the display unit is a frame that carries the mainboad and the battery.
The back is the only thing that can be removed like a lid.