This topic is for issues related to the website. This software is not part of the website, but I'll help you with it.
You're using the wrong tool. The paths for Nvidia and Intel should not point to your renderings, but to the software that performs denoising from their respective manufacturers. You should drag your images into the program, and it will then save the processed images in the output folder you select, known as the Output Path.
Something like that.
You download the denoiser here:
Nvidia:
You must be registered to see the links
Intel:
You must be registered to see the links