When moving objects around the work area, you may notice that on certain points your cursor changes to a different icon. This allows you to use that point to snap a moving shape to another.
LightBurn will automatically align your selection to snapping points if you see the cursor change to a snap cursor before you click:
Hold Ctrl/⌘ to toggle object snapping (Disable by default, may be enable if Settings were changed).
Hold Alt to make snapping 'stickier' - you can snap to things from farther away.