The commenters often tell me I must be using a Mac or a Windows PC for video editing. Nope! I use three important pieces of free and open source software in order to make these videos, and luckily ...
You're likely using the standard open source AMD driver, which should be fine.
At least for me, when I open Kdenlive (using the Flathub version), click on Settings at the top, then 'Run config wizard', it brings up a menu to let me select what hardware acceleration I want to use (since I have both AMD and Nvidia), and it seemed to default to using the VAAPI AMD acceleration.
What does it say for you in the Run Config Wizard menu?
Yes, unfortunately Kdenlive still has a ways to go when it comes to hardware acceleration. I think it's mostly the MLT Media Engine that's holding it back.