if you want a button that you can put portals to your own spaces on, fill out the form at the bottom of this page. the json file should be structured like the example below and can be hosted wherever you want (i recommend github/glitch)
[ "https://lunartiger.github.io/banter", "https://lunartiger.github.io/banter/story-time", "https://lunartiger.github.io/banter/gravity-cube" ]