The CB Gravatar Field is a Community Builder add-on and needs to be installed using the Community Builder Plugin Management page.
The installation process steps are:
- Access the CB Plugin Management page from administration panel using the menu:
Community Builder --> Plugin Management --> Install New Plugin - From the Upload Package File tab click the Browse button
- Select the CB Gravatar package you downloaded
- Click on the Upload & Install button
- You should now see a CB Gravatar row in your Community Builder Plugin Management page
and you should also see the Field cb_gravatar.
After you install the plugin you need to publish it.