I bought this Benchtop Power on Alixpress for 8,00$. It has 3 holes on each side for mounting, so the picture on the e-commerce is wrong.
I cut and insulated other ATX wires inside the power supply.
Then I created this holder using FreeCAD to mount the PCB on the top of the power supply, with the aim of reducing the volume required for the 3D print.
If you want to modify the holder for different hole position I attached the FreeCAD file.
Sliced with Slic3r and printed in PLA using my Wanhao D6.
It seems quite robust.
I imported 2 object in slic3r and the flipped then latter.