How to try new Generative Fill tool?

I've been hearing about this new Generative Fill thing and am interested in at least taking a look at it. I launched Photoshop for the first time in a while recently (directly from Lightroom by right-clicking on an image and selection edit in Photoshop) and a message briefly came up about it but disappeared as soon as the image loaded! Now, though, even that brief message no longer appears. Bottom line: how do I actually install this function? I've seen some content about it online, but it seems to prompt me to actually install Photoshop itself as opposed to just Generative Fill. Can I not just add it to the copy of Photoshop I already have? Hope that makes sense. Thank you.