When I struggled to build Flutter development environment with Android Studio in Arch Linux, I sometimes met the situation where Flutter menus were missing.
I installed Flatter and Dart via pacman and also "Configure"d "Plugins" of them on Android Studio. The start menus didn't show, however, Flatter menus.
I could create only Android projects🤕
The window of Android Studio start menus is expandable. Resize the window if possible:
It may be because Android Studio is configured before Flutter configuration is completed. Restore the default settings:
... and Flutter menus will appear🙂