Slack to To-Do Flow

I found this brilliant flow that I attempted to follow and give me some much needed function. id like to be able to create to-dos right from within slack., The article I followed is posted here: https://tinyurl.com/djwepthb.

I got a little lost at the get input variables and conditions but I thought I hammered through it. Apparently not. My flow is failing with the error: "ExpressionEvaluationFailed. The execution of template action 'Get_Input_variables' failed: the result of the evaluation of 'foreach' expression '@triggerBody()?['$formdata']' is of type 'Null'. The result must be a valid array." I see lots of mentions of this error throguth out these boards but not being familiar with development or flow the results mean very little to me. I'm hoping I can post some shots of my flow and maybe have one of you look at it and comment?