Filled the gap causing overhangs at the base of the top and bottom parts. Slicer shows it as one piece. No supports needed at all for this print.

I used a marble filament (215C nozzle, 60C bed) but my Cura5 settings need tweaking to fix the stringing on the hinge rings.

I didn't add the text to the top cover, and kept the single-layer spacing. If you want the 2-tone look, check the original Flipper Zero Case for the YouTube video and text STL.