This is astounding to me... I looked up this question when I started using Fusion - 7 years ago - and what seems like a simple thing was not available. I came back to it today to find it is still not available and the resounding answer is - you don't want to do that!?!?! SMH
My current need is to print the rough sketch so I can take it to the item I am modeling so I can measure and mark the sketch with precise dimensions. After the model is fabricated I want to use the dimensioned sketch to mark precise locations on the object for further modification. The sketch will later be used to share details to other parties about the object.
This is not complex nor a unrealistic need. So stop telling people they have no need to print a sketch. Just stop.
I tried using the "capture image" tool but it is basically of no value. It does save the sketch with dimensions, but it also includes the X and Y axis and their scales. I don't want them, especially for the last (sharing) step.
The best I could do is a screen capture, which is not part of Fusion.