In case it is not obvious ( for me it wasn't ), you can only acceess the puzzle through github login button.
Registering doesn't give you access to the puzzle.
Thanks for pointing that out, my first thought was the goal is to decode a bit pattern from the flickering neon sign mp4! That would have been some wasted time...
That was definitely my first instinct. I got as far as the morse code decrypts to "NETE" before coming back here to check if I was doing something wildly wrong.