ZyBooks can be added to your course as an Assignment (with grade passback to the grade center) or as an External tool (with no grade passback).
If you are creating an assignment, please note that zyBooks sends scores as percentages, not points. Therefore the point value in Canvas does not have to match the point value in zyBooks. Canvas will convert the score to the correct point scale.
You will first need to create the zyBooks link in Canvas and then you will need to configure that link within zyBooks. Please see How to link a zyBook assignment/section/TOC to an LMS for full instructions.