How do i use Vulkan?

Hi guys im new here.

So the thing is that I'm trying to play KH 1.5 Remix but i get a very low framerate during game/combat

And i have read that vulkan improves this, but when i go to change the renderer "OpenGL" I dont find that option.

Am I missing something?

My gpu is a gigabyte r9 270x 4GB

Thanks for your time