apim-developer-portal2/src/components/help/articles/domain.html

API management developer portal

<p>
    By default, your API Management service instance is available through *.azure-api.net subdomain (e.g.
    contoso.developer.azure-api.net). You can also expose the service through your own domain name, such as contoso.com.
    <a href="https://docs.microsoft.com/en-us/azure/api-management/configure-custom-domain" target="_blank">Learn
        more</a>
</p>