Need Custom Image Tab in Generative Fill tool.

Hello All
I am new here but have been using Photoshop for quite some time. I have a Public Beta Version of Photoshop which has the marvellous Generative Fill tool. I have heard that Photoshop is developing this tool to include Custom Image tab in the dialog box, which would allow the selection area to be filled with a custom image. Unfortunately this Custom Image tab does not appear in my version but I have heard one can request to get it. How can I request and to whom? Thanks