Step 1 : Go to Azure Portal

Step 2: Once signed in, click on App Registrations

Step 3: Click on New Registration

Step 4: Enter Go GST Bill in the Name field, select the Supported Account Type as shown in screenshot below, and then add Redirect URI given below then select Register button

Add the following URL in the Redirect URI box:
https://bill.gogstbill.com/gst/microsoft_auth_callback.php

Step 5: Copy Client ID (And Tenant ID if work or school account), you have to enter this Client ID on Go GST Bill Portal

Step 6: Click on Certificates & Secrets

Step 7: Click on New Client Secret

Step 8: Add a Description for the secret and select an expiry time
-After expiry time you have to generate secret again

Step 9: Copy Value field data, you have to enter this Value on Go GST Bill Portal

Step 10: Enter your Outlook email in SMTP Username, Client ID that we copied in Step 5 and client Secret that we copied in last step and click Save button

Step 11: Click on Authenticate button

Step 12: Login with your Outlook account and click on Accept button

Step 13: If authentication is successful then it will show Disconnect Account button.