How to call a process from Message End Event

[StephenOTT]

How do I send a message from one process to another?

You have to execute the message through a expression, java delegate, or script. here is a simple example to get you started using a expression: ${execution.getProcessEngineServices().getRuntimeService().createMessageCorrelation("message_bar").correlateWithResult()} see: https://docs.camunda.org/javadoc/camunda-bpm-platform/7.8/org/camunda/bpm/engine/runtime/MessageCorrelationBuilder.html for more API options.