I am totally newbie in 3D design world and I've started with Blender.
Since I wanted to test a better render (and fastest) than Cycles, I'm trying with Radeon ProRender.
Now I have a problem: world shading does not render using Radeon ProRender (which does work with Eevee and Cycles renders), is like does not exist.
The world in my scene example is a just simple background with low density (so later I can use it to make a Fog effect).
I am using Blender 2.90, Ubuntu 20.04 and amdgpu-pro-20.30 driver (since latest driver breaks Eevee render by showing graphics glitches, any idea why?).
My graphic card is an XFX RX580 - 8GB Ram
Thanks in advance.
Attached the scene. Like I said, I can't make the added Sun to work using this render.
Also, Is there a detailed docs of how to use this render? Since there are common stuff, when I use Eevee or Cycles renders that does not work here, like adding a simple material to an object (or what I can't manage to work, a material to an object face).
Your scene is just underlit by World light and Sun light.
The Sun&Sky World mode generates image with sky color and sun disc based on settings of this tab. Using it one doesn't need to use Sun light at all. The altitude value of 0.11 degrees(taken from scene provided) makes sun nearly below horizon thus leaving nearly no light.
The "IBL" mode with color only would be much more suitable to reflect you Cycles World setup.
The Sun light intensity is calculated differently by RPR than in Cycles that's why values you were using are just too low to give any meaningful result. By rising intensity by 10-100 time one would see the difference.
In short: workaround is to rise the Sun light intensity to see the difference. Use the IBL World mode with dark blue color of your choice to get the dark blue overall light.
It looks as if the Sun light source have some issues(no light produced at all) in "High" mode for some reason... but works correctly in all other modes. Will look into it.
Here is slightly adjusted scene to show the different settings options(note: I've also turned off the Sun disk in World->Sun&Sky settings), I hope it helps