Check if the user assigned an anchor entity through the Sumerian web editor. If not, use a self-reference to the entity that owns our script component.

AnchorPositioning.js

// Check entity that will get the anchor component
// -------------------------------------------------------------------
// Allow providing a specific entity in Sumerian where
// the anchor should be located in the scene hierarchy.
if (!this.anchorEntity) {
	// Fallback: if the developer didn't set an entity in the editor,
	// use this object (self).
	console.log("no anchor entity provided - use self");
	this.anchorEntity = ctx.entity;
}