To
@lanceventa and others:
For the record (and as a totally blind person, I should know) what is being referred to as the "Like" button using a desktop with Firefox is actually a link and when you press that link, it automatically creates a "like" graphic on the post.
@Josh Owens, One thing you might try with this sight (I actually haven't done it myself) is to use a different browser, such as Microsoft Edge (many of whose commands are similar to the commands used by the discontinued Internet Explorer) and/or Chrome. It is possible that using either of these two browsers (or even some minor players) that the keyboard entries not available in Firefox may be available in any one of them. Good luck!
@lanceventa and others:
As a totally blind person myself, I can tell all of you that what you are referring to as the "Like" button is really a link in Firefox. And pressing the enter key on that link automatically creates the "Like" graphic with the word "like" being read by the screenreader.
@Josh Owens:
One idea I would recommend (I should have recommended it before but I haven't done it myself) is to view this site using a different browser (Microsoft Edge and Google Chrome immediately come to mind). It turns out that different browsers have different quirks and it is possible that what is not available through Firefox might be available through another browser. Good luck!