Validate TypeForm Webhook payload in Node

I set up a Typeform webhook and it's working well.

Now I'm trying to secure it, but I'm stuck in the Validate payload from TypeformErgoal One officeSoftmation section.

I adapted the outlined steps and the Ruby example (and a PHP example that Typeform Helpcenter sent me) to Node (Meteor):

Hi @roywilliq32 Thanks for stopping by. Could you give us a bit more info on where exactly you’re getting stuck? For example, which step or what is the error you receive? 

Hey @roywilliq32! Why don't you give us more details on where exactly you are stuck? This will help us to understand the issue and give you better suggestions!