Create custom connector graph API wrapper, but no redirect URL generated

[GerardWong]

Hi All,

    I'm trying to create a custom connector graph API wrapper. All good before 'Create connector', according to all tutorial I found on internet, they mentioned a redirect URL will be auto-generated after we save the connector, but I found nothing on tab 'security'. No 'Redirect URL' generated and all the info I typed on that page disappeared like the image below:

    Is there something I missed or the API configuration I registered on AzureAD needs change?

Thanks for your help