Custom Flag Not Showing

Hi there, thank you for the amazing work on this! I have followed the super guides on how to do this and have done everything correctly (I sure hope as it’s pretty clear) but the images still do not show.

I made a video of what I am doing just to confirm my steps if I have missed something: https://imgur.com/a/pfySyf8

Any thoughts?

Thank you.

The page I need help with: [log in to see the link]