Taggg syncs with your Google contacts using the People API if you have it toggled on in Settings here https://share.inturact.com/p9ukKxoE.

When toggled on your account will look for new contacts every 24 hours to sync to your Taggg account. Keep in mind in order for a contact to be apart of the sync it needs to be added as a Google Contact, not just someone you have emailed in the past. You can add new Google contacts here https://contacts.google.com/.

You can also add a new contact in Taggg directly in your account under Contacts > New Contact.