YouTube Analytics API authorization issue?

Question

I work with analytics for organizational YouTube channels for my employer. I've been successfully retrieving data using YouTube DATA API, however I am unable to obtain metrics from YouTube Analytics API (a'la reports.query).

Here are the particulars... Authentication: SAML (organizational GSuite account) Authorization: OAuth2 My organizational account is an "owner" (though not primary owner) of the YouTube channel. Google Cloud Platform project: internal (organizational)

I've tried various SCOPE combinations.

When I specify ids="channel==<channel_id>", I receive a 403 (forbidden) response.

When I specify ids="channel==MINE", I get a 200 status with headers but depending on dimension and metric selections, either no records, or a single record with zeros for each metric. My suspicion is that "channel==MINE" is looking for "my" channel rather than the brand account's channel as it wouldn't know which brand channel otherwise.

My question is, how can I assure that my organizational account can obtain data using YouTube Analytics API as well as YouTube Reporting API? Is there an administrative site that assigns these access rights? If so, where is it?

The following code is essentially sample code from the API Explorer...

import os

import google_auth_oauthlib.flow
import googleapiclient.discovery
import googleapiclient.errors

scopes = ["https://www.googleapis.com/auth/youtube.readonly"]


def main():
    # Disable OAuthlib's HTTPS verification when running locally.
    # *DO NOT* leave this option enabled in production.
    os.environ["OAUTHLIB_INSECURE_TRANSPORT"] = "1"

    api_service_name = "youtubeAnalytics"
    api_version = "v2"
    client_secrets_file = "client_secret.json"

    # Get credentials and create an API client
    flow = google_auth_oauthlib.flow.InstalledAppFlow.from_client_secrets_file(
        client_secrets_file, scopes)
    # credentials = flow.run_console()
    credentials = flow.run_local_server()
    youtube_analytics = googleapiclient.discovery.build(
        api_service_name, api_version, credentials=credentials)

    request = youtube_analytics.reports().query(
        ids="channel==MINE",
        startDate="2020-09-01",
        endDate="2020-09-30",
        dimensions="day",
        metrics="views",
    )
    response = request.execute()

    print(response)


if __name__ == "__main__":
    main()

The code as shown, yields...

{'kind': 'youtubeAnalytics#resultTable', 'columnHeaders': [{'name': 'day', 'columnType': 'DIMENSION', 'dataType': 'STRING'}, {'name': 'views', 'columnType': 'METRIC', 'dataType': 'INTEGER'}], 'rows': []}

With ids set to "channel==UC6L0DBYWqAkmwfawTUMaR3g", the followiing is returned...

googleapiclient.errors.HttpError: <HttpError 403 when requesting https://youtubeanalytics.googleapis.com/v2/reports?ids=channel%3D%3DUC6L0DBYWqAkmwfawTUMaR3g&startDate=2020-09-01&endDate=2020-09-30&dimensions=day&metrics=views&alt=json returned "Forbidden">