I have the very same problem. What is more, the traffic is recorded after I click the getButton as seen in the Google Cloud Platform Dashboard:
But nothing happens on the website. Is it the same in your case @tom.nahas?
Do you think you could help us @yisrael-wix ?
PS. The instruction I followed: https://www.wix.com/velo/reference/velo-package-readmes/google-sheets-integration