I assume you need a lesser space between the rich text and the field. However, the length(width) of the field is adjustable, and the drag and drop will position an element, just next to the field. The Label and Field are selected together. However, if you want the text to move/appear closer to the Label(which may appear a bit far away if your field has a bit more width), you can resize the field. This shall bring the text closer to the label. That being said, the text still remains at the same distance from the field as earlier.
You can try like this;
1. Drag and drop the rich text
2. Resize the filed with the icon highlighed in red below