Unfortunately, development for AMD ProRender seems to be stopped for Blender prior to 2.8. I am using 2.79, since 2.8 and above still has major issues for my workflow. Anyway, ProRender still works nicely on 2.79, which is great!
The only thing that I couldn't make work is using a shader's refraction's transparency on the .png image output's alpha channel. This would be very useful! So I decided trying to set up the scenes in Blender 2.79 and just render in a newer Blender version. So I installed Blender 3 and the newest AMD ProRender version currently available that also states Blender 3 support.
However, unfortunately, any attempts to render using AMD ProRender crashed Blender. I tried installing 2.93.7 LTS, which I thought might be more stable, installed ProRender, but again, when using AMD ProRender for rendering, I only get crashes. The builtin renderers work fine, though.