Input Shape - connect the Shape to sample its bounding box.
Expand - increase the size [x,y] of the bounding box.
Position - outputs the position of the Input Shape.
Size - outputs the [width, height] of the Input Shape.
Create a Basic Shape (rectangle).
Create a Text Shape and a Bounding Box.
Connect textShape.id > boundingBox.inputShape.
Connect boundingBox.position > basicShape.position.
Connect boundingBox.size > basicShape.size.
Your text will have a rectangle behind it which will update when you make changes to your Text. Note - make sure you have the Rectangle under the Text in the Scene Window and that your Text and Rectangle are set to different colors 😉