Please go to Google APIs console page https://developers.pinterest.com/apps/ in the API access tab, create a new client ID, and in the line 22 set the client_id to Client ID and client_secret with Client Secret. The callback URL must be http://erp.leaf.com.my/webmail/modules/OAuthIntegratorWebclient/Classes/OAuthClient/login_with_pinterest.php but make sure the domain is valid and can be resolved by a public DNS.