After you have inserted a dart, you can easily snap the legs or the apex to various locations.
On the Main toolbar, click Select.
If editing the dart apex or a dart point, on the Horizontal contextual menu, ensure Edit Points is enabled.
Go to the Horizontal Contextual menu.
Select the Snap to option you want to use.
Note
When you edit an existing dart, the dart points and the apex can be snapped to the grid and to the guidelines.