How to pass color information to compute shader?

I’m very new to the topic of compute shaders in unreal engine and i followed a tutorial to write to a render target from a compute shader.
The shader writes to a texture that is passed as a new FRDGTextureRef that is created from a FRDGTextureDesc.
Now, i would like to fill the FRDGTextureRef with data before i pass it to the shader.

Is that possible?
Or is there another way to pass texturs to a compute shader?