That was it, ok now I feel stupid.

Oh man, I even read all the comments and still couldn't find it when I finally clicked on the image link. Terrible UX.

cc: @apenwarr (tailscale founder), might want to have someone fix this and move the close button to the top right of the modal, not the bottom right.

You’re not stupid. That’s terrible UX. The button is completely disconnected from its modal, and is placed in a bizarre/nonstandard location.