If your site is a client, then the REST API is not enabled, but the user interface for adding your events to other site’s is enabled. You will have an interface for adding endpoints, or URLs that this site can attempt to send events to.
Settings
The API key entered for endpoints must be that provided by the API server. This is the default API key; if you’re using multiple endpoints, each endpoint can have a unique API key.
URL: The home URL for the My Calendar server.
Label: The label that will be displayed in the user interface for selecting where to send events.
Author: The author ID that should be sent as the author on the remote site. This will probably not be an author ID that exists in your site, so you will need to be provided with an appropriate author for the target site.
Key: The API key for the target API server. If left blank, queries will use the API key set globally.
Cross Posting Events
When the site is a client, any configured servers will be shown in the admin ‘Add Events’ interface as options to select for target. The events will always also be added to the current site.
Cross posting is not available from the public submissions form.