Sorry for not being more clear. That script I included is in a Scripting block in Airtable. Clicking the button in a record triggers the script, and the script makes the webhook call behind the scenes. In your case, you might be using the URL setup for the button and just calling the webhook directly, which will open a new window/tab. I just prefer the script version so that I don’t have to unnecessarily open a browser tab.
In Integromat, the webhook receives the record ID, and then the “Retrieve a record” module uses that ID to pull the full record from Airtable. In my case, the next module is CloudConvert, where I’m passing in data from the Airtable record to convert from HTML to PDF, but in your case you’d pass specific field data to Google. I haven’t tried using Google document templates yet, so I can’t offer specific guidance beyond that.
If the setup you’ve created is essentially the same, but Google is still creating documents for multiple records, could you share screenshots of the setup dialogs for your Integromat modules? Perhaps something in there can shed some light on the issue.