I needed an adapter to attach my Solar Panel to my balcony bar, so designed adapter that would screw using the 2 holes at the base of the solar panel. I've did 2 versions, one with no incline and the other with 10Degree, this fit perfectly for me to be positioned on for the sun.

I just used 2 M4*16mm screws and 2 M4 nuts.

Just print on the side as the attached photo, I printed my second one with supports due to my printer cooling not being great, but should be printable without supports.

Printed in eSUN White PLA+, 25% infill with 3 walls.