Working Title, you guys rock!

Hi, I’m new to the WT CJ4 and am trying to learn how to use the autopilot. I’m trying to use it with flight plans I create but have had no success. Does this require knowledge and use of the on board flight computer (which I know nothing of yet) too?
I’ve been able to use the AP on the FBW 320 without use of the onboard flight computer by only using my created flight plans.
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The YouTube videos I’ve seen to date always seem to show AP in conjunction with the flight computer.

Thanks for any assistance!