What is "Your Access Token" in Youtube Data API and how to get it?

Question

I got some code from youtube data API's try-it editor.

I have some curl code here, I have the API Key, but I don't know what [YOUR ACCESS TOKEN]is. I've been trying for the past two hours to find something, but couldn't get what I wanted.

I had an Oauth 2.0 client ID [742151xxxxxx.app.googleuserconsent.com] in google developers console.

I used it in place of [YOUR ACCESS TOKEN] but still got the authorization error.

Here is the cURL code:

curl \
  'https://www.googleapis.com/youtube/v3/playlistItems?part=id%2C%20snippet&playlistId=pbsF2UOcspaGQkAe1BCAR395sue-tp5r&key=[YOUR_API_KEY]' \
  --header 'Authorization: Bearer [YOUR_ACCESS_TOKEN]' \
  --header 'Accept: application/json' \
  --compressed

Here is the error JSON:

{
 "error": {
  "errors": [
   {
    "domain": "global",
    "reason": "authError",
    "message": "Invalid Credentials",
    "locationType": "header",
    "location": "Authorization"
   }
  ],
  "code": 401,
  "message": "Invalid Credentials"
 }
}

Answer 1

Clicking the question mark next to credentials in the try it editor provides some more information about the different authentication types offered,

The google OAuth 2.0 Client Libraries offer a further explanation about the access tokens and how to obtain them including some pre-made libraries in a few languages.

https://developers.google.com/identity/protocols/oauth2#libraries