i think it would be cool to allow 3rd party plugins like allow other effects from differentediting software!
Hi @Deroxist, and welcome to the forum and community.
I agree this would be cool but we would need to find someone to code it. Can you?
There is a roadmap item for OpenFX support but this is still a few years out. Again, if a developer wants to take this on earlier, we will not stop them 
No I cant code I dont have experience with coding sorry
I also have another question is it possible to do any motion graphics in kdenlive like stuff from after effects or premiere pro?
Yes, but you have to differentiate.
You can use the Transform effect to move, size, and rotate clips with keyframes that support easing. See this section of the manual.
You can use Glaxnimate from within Kdenlive to create vector graphics with animation. See this section in the manual.
The manual has a pretty good search function, and I highly recommend looking through it before asking basic questions in the forum
Check out the new upstream mlt PR for OpenFX: OpenFX Module by joinlaw · Pull Request #1186 · mltframework/mlt · GitHub
Related forum thread: Basic OpenFX Support development log - #5 by luzpaz