How to add dimensions?

I’ve got a layout with a bunch of objects. I’d like to know the distances between important points. But I don’t see any way to add dimension lines to the Dimension Lines layer. I also searched Help for “Draw dimensions” and it came up with nothing. How do I add dimensions?

On the “lines and arrows” menu button in the Drawing toolbar you’ll find the “Dimension Line” tool

I have tried the above answer, but it still does not work. please do a video on how to add dimensions.

Gerard How