I can't seem to find any OpenGL headers for the RTX ray tracing extension, seems like they only want you to use Vulkan and optix with RTX
Is your question whether or not OpenGL headers exist for the RTX extension?
It appears it can only be accessed through NVIDIA OptiX, DXR, and Vulkan.
From the website:
Developers can access NVIDIA RTX ray tracing through the NVIDIA OptiX application programming interface, through Microsoft’s DirectX Raytracing API (DXR) and Vulkan.
There's an extension already, though I'm not sure how finished it is: GLSL_NV_raytracing.