site prefix? example
Twitch no https://www.twitch.tv/pocketwatch
Twitter no https://twitter.com/wikipedia
Github no https://github.com/torvalds
TikTok yes, @ https://www.tiktok.com/@nytimes
Instagram no https://www.instagram.com/nytcooking/
Facebook no https://www.facebook.com/zuck
GitLab no https://gitlab.com/cdignam
Reddit yes, /u/ https://www.reddit.com/user/thesoundandthefury/
Steam yes, /id/ or /profiles/ https://steamcommunity.com/id/pentadact/, https://steamcommunity.com/profiles/76561197985016861
HN yes, /user?id= https://news.ycombinator.com/user?id=pg
YouTube yes, @ https://www.youtube.com/@TomScottGo
SoundCloud no https://soundcloud.com/wearemichelle
Bandcamp yes, w/ own subdomain https://mitski.bandcamp.com/album/the-land-is-inhospitable-and-so-are-we
Pinterest no https://www.pinterest.com/nytimes/
Dribbble no https://dribbble.com/github
Figma yes, @ https://www.figma.com/@primer
Mastodon yes, @ https://hachyderm.io/@mitsuhiko
Bluesky yes, /profile https://bsky.app/profile/danabra.mov

An even split – seems like newer sites prefer the prefix which saves a lot of headache.