Use the below steps to create the Client Secret value from the Azure portal:
1. Log in to the Microsoft Azure portal.
2. Search and navigate to the application you have created for monitoring.
If you are unsure about the application name, you can navigate to the Edit Azure monitor page (click the hamburger icon near the Azure monitor name) and copy the Application ID and paste it in the search bar of the Azure portal.
3. Under Manage, click Certificates & secrets.
4. Under Client Secrets, click + New client secret.
5. In the Add a client secret window, provide a Description. Select your preferred period in the Expires field, and click Add.
6. Copy the Client Secret value in the Value column and save it for later use. Copy and paste the value as soon as you see it since the value disappears in a short span of time.
Make sure you copy the value under the Value column and not the Secret ID column.