In order for an event to appear on an event campaign map, hosts must click the host button on the main map page and create the event from there. Creating an event in any other way will result in an event that's not connected to the event campaign, and therefore not on the map.
If an event has already been created, the host can either create the event from scratch (using the host button on the main event campaign page) or the host can reach out to the organizers of the event campaign. More here.
Note that if you did correctly create your event by clicking the host button, and your event is sponsored by the larger organization hosting the event campaign, depending on the event campaign there may be a short delay in populating the map.
For our step-by-step guide for local event hosts for event campaigns, click here.