Build with Xcode fails

I built a vue3-vite project with ionic and starting the simulation with the Ionic VSCode extension just works fine.
But running ionic cap run ios --live-reload --external does show a screen only with background color.
Running ionic cap build iOS makes Xcode start but not building the project.

My Current project is found herehttps://github.com/Patsch36/sweatflix, current commit-version is 88a2f67.

Thanks for your help.