Per the documentation
The core of Home Assistant is the event bus. The event bus allows any integration to fire or listen for events. It is the core of everything.
Is there a way to fire events into the bus? Ideally I would except to see this as a callable service “Fire/Create Event” but there doesn’t seem to be any service available. Is there any to achieve this natively?
I know that I could use MQTT as a secondary event bus, but I would rather not add an extra component to my process if I can use the core components.