STEP-1
Go to, https://console.developers.google.com
STEP-2
Create new project Google Console Project
STEP-3
Select console project, Click library and enable Admin SDK library API access
STEP-4
Create OAuth Client ID
STEP-5
Configure product name in Consent Screen if asked.
Note. Make sure to authorize domain ( googlegroupsync.ilaesolution.comĀ )
STEP-6
Configure authorized re-direct URI's with below callback URL
https://googlegroupsync.ilaesolution.com/google
STEP-7
Copy client_id and client_secret from created OAuth Client.