Spawn not working

[ddv]

I just started using Tyflow today. I tried to emit children by travel, but it doesn't give birth to any children. It only emits children when I choose "per frame" or "per step". None of the other spawn mode work. What have I done wrong here? Or it is not working with free version?

[tyFlow]

In the operator's timing rollout, set it to a mode that activates the operator over time (ex: continuous). By default, the timing is set to "on entry", which means particles will only be affected by the operator the first time they enter the event.