There are 2 ways to do that
1-) Go to “about:config” and set “social.enabled” to “true”.
Or
2-) Go to facebook.com/about/messenger-for-firefox
There are 2 ways to do that
1-) Go to “about:config” and set “social.enabled” to “true”.
Or
2-) Go to facebook.com/about/messenger-for-firefox