Open the simulator
In the Canvas view, select Test flow in the header. The panel on the right becomes a simulator and the run starts at the Trigger. If you are in the Steps view, switch to the canvas first, as testing lives there.
Try the conversation
Tap option buttons and type answers just like a customer would. A Collected variables list shows what has been saved so far. Use Reset to start the run again from the beginning, and close the panel with Exit test.
What is real and what is not
The simulator is a safe dry run: nothing is sent, no real messages go out, and no real API calls are made. Integration steps such as Call API, Send to Webhook, AI Collect, Let AI Answer, and Human Handover are simulated, not executed, so a clean test does not prove those connections work end to end.
Good to know
You do not need to publish or even save to test, and it works on an unwired draft. Edits you make during a test take effect the next time you Reset the run.