Compose Now is only available on certain websites, but we are working on enabling it everywhere else. You can find a list of websites we are officially integrated with here: https://composeai.notion.site/Supported-Tools-0f3ee54d5ef04d.... When a website is "experimental", you can force enable the extension (autocomplete) there but may encounter some issues. Thanks for pointing out the Github example—we'll look into that.
