Button can be added to the surface and connected to a buttonhole to be locked.
Design Toolbar > Button
Click on the Design Toolbar, then select Button
Select the desired button type via Left Panel > Button.
Use the Button cursor to click on a desired location on the surface in 2D canvas to create a button.
Select the button via Button Selection Mode to move in 2D canvas and 3D viewport.
Double-click the desired button type to apply via Button Selection Mode (Left Panel > Button).