Only some contacts transferred from iPhone to Android

[Android Central Question]

I did a full itunes backup of iPhone to my Mac, followed steps to sync to Google and it looked like everything had made the journey safely. Sold the iPhone. Now on closer inspection, I realize that a lot of contacts are missing. Assuming those missing contacts are still in that backup (are they?), Can I get them from my Mac to my Moto G6? If so, how? Non-3rd party software solution preferably, if possible. Thanks