https://en.wikipedia.org/wiki/Bookmarklet

https://chrome.google.com/webstore/detail/bookmarklet-url/lnldegfbcpbaloalllolfjbekjkjieom
http://www.michurin.net/tools/bookmarklet.html
https://javascript.ru/unsorted/bookmarklet

2021
https://www.freecodecamp.org/news/what-are-bookmarklets/

samples
javascript:fetch("https://${host}/api/downloads",{body:JSON.stringify({url:window.location.href,format:"bestvideo"}),method:"POST",headers:{'Content-Type':'application/json'}});