@JR Boulay, a Generative fill module has been added to Firefly (Beta) now, but only for a few weeks, so you might have missed the addition! It's also called “in paint” in the URL (https://firefly.adobe.com/upload/inpaint)
@Jay30827735kcuc, what exactly is happening when you try the tool? Can you share screenshots? Did you try switching to a different browser? Let us know more and we'll try to help you.
I just tested it with this starter image from the module's home page using the prompt “hiker” for a selection in the foreground, and it worked quickly with a few good results.