Request access token
POST/token
Exchange the client ID and client secret of an API key for a short-lived access token, using the OAuth 2.0 client credentials grant. This request takes no Authorization header: the client credentials in the body authenticate it. The optional scope value narrows the token to a subset of the key's allowed scopes; omit it to receive all of them. Cache the returned token for its lifetime rather than requesting a new one per call.