Sorry for the typos. This is how it should read when I type slow and I'm not in a rush:

''I used to be able to send a website from anywhere on my iPhone (from the Google app, from Safari, etc.) to a new Firefox tab on my desktop. I miss that. Did I do something wrong to remove that function?

I can send it from iPhone Firefox to desktop Firefox, but that's not what I'm looking for.''

Hi, do not think so. I have no devices I send to so stick with me.

Please go to the 3 Dot Menu ( Page Actions ) in the Address Bar and Click it. You should find your option there Send Tab to Device. As for the definition of a device I do not know but is more than likely to be a phone but you would have to check to find out. This the only thing I could find : https://techdows.com/2017/09/firefox-57-page-action-menu.html

Sorry, but that only works from within Firefox. I want to use it from anywhere on my iPhone...

So your question is about everything on your iPhone other than Firefox? This forum specialized in Mozilla software. If no one here knows the answer to a general MacOS question, please try Apple's forums.

You're right. I was looking for Firefox/Mozilla to say that nothing has changed on this side. I thought it was a Firefox function that extended into iOS and allowed me to SEND TAB. I know it was there for years and is not there anymore. Trying to get an answer out of Apple is not easy.

btw - Thank you both for helping!

Welcome.