https://addons.mozilla.org/addon/right-links/versions/beta Увы, с ограничениями (WebExtensions позволяют реализовать только часть старых возможностей): https://github.com/Infocatcher/Right_Links_WE#issues
Yessss, thanks so much for this add-on..I have searched and searched for ways to open YT videos (on side bar) without always right clicking, and scrolling through the menu....I LOVE IT! SO HAPPY TO SEE THE DEVELOPER HAS IT WORKING IN FF QUANTUM.
The long left click should become the standard behavior universally for all browsers. It has become my number one Add-on and I don't even use the other features. Please rewrite it with WebExtensions! If needed I will make a significant donation to get it done.