Flatpak run - error: No remote refs found similar to ‘flathub’

Thank you for your assistance. As I move forward with the process I need to disclose that I am one of the developers on the Greenery Wallet project.

The link to our homepage is in the appdata.xml file. With the research that I have done I see that apps like Firefox are doing binary releases with special keys. Do I need to setup a special key while submitting Greenery as a Binary Release?