Each GeoDirectory post type has a setting that stops listings of that type being added from the frontend. Turn it on and you can still add and edit every listing in wp-admin.

1. Go to Places > Settings > General (or the same screen for your other post types).
2. Click Show Advanced.
3. Tick Disable frontend add.
4. Save the changes, and repeat for each post type you want to lock.

After this the add listing form will not load for that post type, for anyone, and the frontend edit form is blocked as well because it uses the same page. Remove any Add Listing links from your menus too, see Menu items.

Adding listings in wp-admin

Go to Places > Add New (or the Add New link for your post type). The GeoDirectory fields, including the address and map, custom fields and images, appear on the edit screen. See Create a listing in the backend for a walk through.

If the GeoDirectory fields are missing on that screen on a multisite network, check that GeoDirectory and its add-ons are activated on each site and not network activated, see Can I use GD on WordPress multisite?.