Reference image not appearing when using Generative Fill

[image_editing_beginner]

I am using a MacBook with an M1 chip, and Photoshop version 25.12 (which I believe is the latest version). When I select an object and attempt to use Generative Fill with a reference image, the button for this feature does not appear (please see the screenshot below). Has anyone encountered this issue or know how to resolve it?

[Ged_Traynor]

@image_editing_beginner it's still in Beta as far as I'm aware.

https://community.adobe.com/t5/photoshop-beta-discussions/new-beta-firefly-model-for-generative-fill...