A simple search for “Kdenlive GPU rendering” would have resulted in many hits saying that until the movit library is fixed, Kdenlive does NOT have GPU support for playback etc., and that GPU rendering is limited to the ENCODING part of the rendering process, and only if the respective profile is selected (NVENC or VAAPI).
Please do some due diligence (aka internet searches) before posting a question.
Oh, and BTW, there are not that many professional video editing applications out there that truly have GPU rendering.