QueueService
To send a Spark message, you must first place the message into a Vault queue with QueueService. You must do this within a Vault extension. For example, a trigger or action can call QueueService to add a message to a queue.
You must deploy your Vault extension to make it available for configuration in your Vault. You can view all of the extensions currently deployed to your Vault in Admin > Configuration > Vault Java SDK.
Learn more about QueueService in the Javadocs