Initial and send a message to a Microsoft Teams channel using Bot Framework SDK v4 for Python

I was trying to initial and send a proactive message to one Microsoft teams channel with the help of below example: I added this code to the example in order to initiate a message: But it didn’t work, and I tried many different ways and none of them worked too, always the error is: I don’t know what is my problem here! Answer Ok, last night Microsoft added a new python sample which solved this issue: