We need to install the PublishPress Content Calendar and Notifications plugin before executing this recipe. Take the following steps to install the plugin:

1. Log in to the Dashboard as an administrator.
2. Click the Plugins | Add New button.
3. Search PublishPress in the Search plugins field.
4. Once plugins are listed, click the Install Now button of the PublishPress Content Calendar and Notifications plugin.
5. Click the Activate button to activate the plugin.

Now, you are ready to start this recipe.