Firefox did not have the menu item for me, I had to go into about:config dom.text_fragments.create_text_fragment.enabled

Doesn't appear supported in Firefox 128 LTS. No highlighting whatever I do. Thanks though, maybe it turns up in some later version.

	▲	extra88 2 days ago \| parent [-]
		Text fragment linking was added in Firefox 131. Firefox 140 is the newest Extended Support Release (ESR) so it can follow such links but I don't know if the context menu has the option to create them.