Why is the Generative Fill button not available?
If you find that Generative Fill is greyed out for you, it is possible that you may not have a valid Date of Birth associated with your Adobe ID account. To update your Date of Birth, you can do any of the following:
• Log into Behance with your Adobe ID and enter your Date of Birth.
• Log into your Adobe account and enter your Date of Birth. To learn more, see Error: "Not eligible to use Creative Cloud services".
Once your Date of Birth is up to date, relaunch the Photoshop (beta) app to enable Generative Fill.