Google Apps Script error - Executions on HTTP endpoints are disabled. Set enableHttpEndpoints to true in manifest file

In a Google Apps Script, I'm trying to use a Cloud Function URL as described here

But I'm getting an error:

Executions on HTTP endpoints are disabled. Set enableHttpEndpoints to true in manifest file.

I've searched all over Google's documentation, stack overflow, and google and can't figure out where to put that enableHttpEndpoints: true. Anywhere I've tried results in an invalid manifest error.

{
  "timeZone": "America/New_York",
  "exceptionLogging": "STACKDRIVER",
  "addOns": {
    "common": {
      "name": "name",
      "logoUrl": "logo",
      "homepageTrigger": {
        "runFunction": "firebase functions URL here"
      },
  }
}

Solution 1:

There is no mention to any enableHttpEndpoints in the documentation (which can be read here), nor there seems to be any response to the call. This is an issue that has been reported in Issue Tracker:

https://issuetracker.google.com/214015254

You can click the star next to the issue number to upvote it and give it more visibility.

Meanwhile, I would suggest using endpoints with an https:// prefix, as it is stated here that http:// endpoints are not accepted.