Mar 05, 2020 Launch the Contacts app on your Mac. Click on File in the menu bar at the top of the screen. Click Export. Click on Contacts Archive. Name the save file, choose where you'd like to save, and click Save. Source: iMore. From here, you can do whatever you want with the saved file. Upload it to Dropbox, Google Drive, or save it on a physical backup.
Contacts User Guide
You can export selected contacts to send to others or to import on another computer. Or archive all your contacts so you have a backup copy of them.
Note: To exclude notes and photos when you export contacts, choose Contacts > Preferences, click vCard, then deselect “Export notes in vCards” and “Export photos in vCards.”
In the Contacts app on your Mac, do any of the following:
Export some contacts: Select contacts or a group, then drag them to the desktop. Or select them, then choose File > Export > Export vCard.
The contacts are exported as a vCard file (.vcf).
Export all contacts: Choose File > Export > Contacts Archive, choose a location, then click Save.
The contacts are exported as an archive file (.abbu).
If you made your card private, fields you opted not to share are not included when you export your card.