I believe these are the ones I used: https://www.hobbylobby.com/Crafts-Hobbies/Dollhouses-Miniatures/Building-Electrical-Components/Miniature-H-Hinges-with-Nails
But really any dollhouse scale hinge should work. These are about 1mm smaller but much cheaper and should do the job just as well: https://smile.amazon.com/dp/B016XSPL88/
I just used the Hobby Lobby ones because I had them on hand from another project. I had to cut the edges of them to fit in the gap anyway.