Incase someone comes to this later, just as I did. I uploaded my first build to steam and this was their reply.
“Caution: During our review the app failed to launch on Windows due to some missing dependencies. These dependencies are caught by the Unreal launcher, however we ask that these dependencies be included with the Steam installation. To resolve this, we have edited your Steamworks settings to include these dependencies automatically. You can view the change by visiting the App Admin and selecting the Installation > Redistributables tab. Please publish this change before releasing your app by using the ‘Publish’ tab. The following common redistributables have been added: DirectX End-User Runtimes - June 2010 Visual C++ Redistributable 2022”
Very nice and helpful of them. Im using 24.7