Firefox does not support those #:~:text links

https://caniuse.com/url-scroll-to-text-fragment

Works for me. Your browser does not support URL Fragment Text Directives[0]. What browser version do you use?

https://wicg.github.io/scroll-to-text-fragment/

Argh sorry, I didn't have time to add anchor links to the site.

Look for "Laconic! (a Twitter CDN)" in the project section.

(Also, weirdly enough, fragment links can be consumed in Safari, but to share them, I need to open the site in Chrome.)