I need google id of the contacts, Is there any way to find the google contact id for my address book contact?
I found this answer, which shows it is possible in Android.
How can I achieve in iOS??
Please help me to find google id from address book.
How about trying to visit this document.
If my understanding is right, you need this Unified Contacts.
You can also refer from these SO post 1 and SO post 2 for further details.
Try also the suggested code in this SO post.