Portal with RTX is a mod. It is a remake of the original game, designed by nVidia Lightspeed Studios, published specifically featuring nVidia DLSS technology. AMD was not consulted or included in the development of this game.
I find it difficult to believe that nVidia would pay a developer to design a sequel game specifically for nVidia hardware and then reach out to AMD for input, or that a game developer would be posting in a public forum seeking assistance contacting AMD resources.
Here's the link to AMD Gaming Solutions. Good luck.
https://www.amd.com/en/gaming.html
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