Invoking AWS Step function from Lambda in python

So, I found the mistake, I was using the wrong ARN. The ARN I was using was for a specific execution of the step function The correct ARN to be used is

arn:aws:states:us-east-1:xxxxxxxx:stateMachine:dev-hassan-pipeline-sf

Its actually surprising, that I couldnt find the ARN for the state machine on the web ui. I figured out my mistake when looking at some sample codes, and I realized my ARN had execution in it and not statemachine.

I just realized, I did not even post the entire ARN in this question