It works the other way round 
- You link the qml page to the service / it’s dbus-paths.
- None, you modify the QML settings menu to show your settings page.
- You design a control in the qml and link it to the dbus-path it should affect.
Just check the original qmls, for example for ESS-Settings, and you quickly figure out how it’s done.
Heres also a quite old service adding a UI component - should give you ideas as well: