Thank you so much. It worked for me!
The only thing I had to add, was some CSS in my theme to make sure that the H5P-content would display correctly on the screen.
I then added the H5P-content through a ''description''-question type in the question pool and put the embed code there through the atto editor. Once I added this description question to my question pool, it all worked fine.
I'm guessing this only goes for my particular case, as I used a large image, but I thought I'd share it nonetheless for people who might encounter this as well.
Once again, thanks for this great addition. It works fine in Moodle 3.6 as well.