Proactive message using botkit on teams

Question

I am trying to add new feature to the bot which is sending the message to some users proactively from the bot. am working on botkit ("botkit": "^0.7.4") and language nodeJS(node v10.24.1 (npm v6.14.12)).

Below is the code sample:

let bot =  controller.spawn({"serviceUrl":"https://*****"});
params = { conversationType: 'personal', 
          tenantId: '66********',
          id: 'a:1*********',
          members: [
           {
            id: '29:1*********'
             }
          ],
          channelData: { tenant: { id: '6********' } },
          is_group: false
       }
bot.startConversationWithUser(params);
bot.say("hello");

Although it is not giving any error, but it is not sending the message. I checked all the documentation but fail to get any solution.

Can anyone suggest a way out where I am going wrong? Which is the right way to send proactive messages to the users on the teams?