I would like to use urlfetch to populate a spreadsheet with page data but the URL that I am trying to use is coming back with an error as an invalid argument. I think the pr
Try using
baseURL + encodeURIComponent(parameterString)
Where you include the parameters you're passing to the base URL you are querying as the value passed to the encodeURIComponent function. This post may be of use to you:
Encode URL in JavaScript?
If you encode the entire URL, like it looks like you are doing above, you're encoding more than just the parameters, which I assume would be where your problem lies.