Google calendar api get error like "domain": "global", "reason": "notFound", "message": "Not Found" - google-api

Question

I tried get list of event from calendar example from here.
No matter which property I
use, I always get the 404 "not found" error. Anyone can shed some light on this? Many thanks.
Request.
POST https://www.googleapis.com/calendar/v3/calendars/oneclapp.2021#gmail.com/events?
key=AIzaSyCGRPF0wSSBLndqdUftlbsDH9emHD_S-qg
Accept: "application/json"
Authorization: Bearer ya29.a0ARrdaM9PPHndl040qaXFmoSFGT9yRPWZs_yrTnYLAHQ0GF-UBvGc67S2L1m0O5OFIilq8oVGRuvw29NFwomtmUTBeHoABcIlaVD_p--4NVlBWCcXLBgfDjsF_5tvt4XRShd1itpe_9CULan9x6BV4TOyP__TkQ
Response
Response:
{
"error": {
"errors": [
{
"domain": "global",
"reason": "not Found",
"message": "Not Found"
}
],
"code": 404,
"message": "Not Found"
}
}

Answer 1

First off events.list is not HTTP Post its a HTTP GET
GET https://www.googleapis.com/calendar/v3/calendars/calendarId/events
Second assuming that you just miss wrote post and you are actually doing a http get.
Not found means just that the currently authenticated user does not have access to the calendar that you are trying to request events for. in this case oneclapp.2021#gmail.com
I recommend using primary to test that you can get the currently authenticated users primary calendar.
GET https://www.googleapis.com/calendar/v3/calendars/primary/events

Answer 2

It looks like you have not configured the OAuth 2.0 Client IDs correctly. We need to configure the OAuth client ID correctly and its type should be 'Web Application'. I was also getting the same error messages, but once I configured the OAuth ID, then it started working.
OAuth id type: Web Application
Permission scopes : https://www.googleapis.com/auth/calendar.readonly, https://www.googleapis.com/auth/calendar, https://www.googleapis.com/auth/calendar.events.readonly, https://www.googleapis.com/auth/calendar.events
Authorized redirect URIs: http://localhost
Here is the screenshot of the Google Calendar API project settings.