I am trying to create custom policies in an Azure AD B2C tenant. But the "Add" and "Upload Policy" both buttons are disabled. Looks like the custom policies have not been launched to date. Is that the case? I searched quite a bit but could not find any document suggesting if custom policies have been launched or not. My requirement is to be able to:
1) Change E-Mail Address 2) Change Password
I predict you are referring All policies blade to upload custom policies.
But, to create/upload custom policies, you must use IEF blade. B2C -> Overview -> Identity Experience Framework - Preview
IEF button default to disable, to enable you must link your tenant to Azure Subscription.
Follow https://learn.microsoft.com/en-us/azure/active-directory-b2c/active-directory-b2c-how-to-enable-billing to link B2C tenant.
On success, navigate to the B2C tenant and you will see IEF blade become active. Use upload button to upload advanced policies.
HTH :-)