It's best to draw by yourself with drawing software. If you can't use drawing software, you can use hand drawing. If it is not convenient to draw by hand, you can explain your technical scheme to the agent in words and ask him to draw it for you. Don't forget, he will give you an agent for a fee. Of course, let him do more, and he may charge more. The scope of agency services, you can look at their agency contract in detail. If the picture is simple, the general agent will help draw it, and generally there will be no extra charge.
What is so important about CAD drawings?
I don't understand ~ ~ ~
For utility model patents, drawings are necessary and indispensable.