I\'m trying to execute API.AI tutorial for building a weather bot for Google Assistant (the one here: https://dialogflow.com/docs/getting-started/basic-fulfillment-conversat
Oh boy, in fact the reason was most stupid ever. I didn't enable "billing" on Google Cloud Platform and that's why it blocked everything (even though I'm using a free test of the API). They just wanted my credit card number. It works now