From this section you can render out of denoised render passes and you can use some of these passes in compositing software according to your needs. If you have not checked the "Use denoised beauty pass" in the Octane Render Settings main section, you should select "Denoised Beauty" from here. This will save your Denoised Render. You mainly use this "Denoised Beauty" pass.
You can see a few examples in the following pictures.