External Events /trigger_intent issue in RASA X 0.42.6 and Rasa NLU 2.8.11

I am using RASA X 0.42.6 with RASA NLU 2.8.11 version and we want to implement a feature where we can send a message to the user after a certain amount of time like,“Hi, long time no see?” or we can wish him “Happy Birthday”. Currently, I am testing it on Facebook messenger but /trigger_intent is on working. as per Logs, I am getting 200 responses but not getting any messages or notifications. I followed the documentation flow. Need help in why it’s not triggering what’s the catch in it? Or is there any other way I can implement this feature using RASA? @akelad