For export to be available,
- Your organization have a 3D Export license and export credits are still available for your license.
- You need to have 3D export permissions, which your account administrator can provide you.
Check with your Nearmap account administrator that they have granted you the correct license and permissions for 3D Export. It is possible that if you do have a 3D Export license, it is on a separate license. If your administrator needs to change the license, they can use these instructions: Manage Subscriptions.