You’re probably missing some dependencies. From the docs:
Install the dependencies (skip gstreamer (~120MB) if not needed, see
Kivy’s dependencies):
python -m pip install docutils pygments pypiwin32 kivy.deps.sdl2 kivy.deps.glew;
python -m pip install kivy.deps.gstreamer
To install these dependencies, open up a terminal (can be a console, Pycharm Terminal window, etc.), run the first command and then the second command.