Youtube caption download API throwing 401 with API key.https://youtube.googleapis.com/youtube/v3/captions/id
"error": {"code": 401,"message": "API keys are not supported by this API. Expected OAuth2 access token or other authentication credentials that assert a principal. See https://cloud.google.com/docs/authentication","errors": [ {"message": "Login Required.","domain": "global","reason": "required","location": "Authorization","locationType": "header" } ]}API is throwing 401 error with API key.