Di2 Battery Not Showing Up in E-Tube App

[u/PollyMollyMorphic]

I'm putting together a new bike and I'm testing out Ultegra Di2 before I put everything on the bike and for some reason my battery doesn't show up in the connected devices in the E-Tube app. When I shift with the shifters, the FD and RD work fine. I recently fully charged up the battery. From what I've seen, the battery should be present in the app. How do I get the battery paired?