Fix typo: configuing -> configuring

Author: changeworld

articles/api-management/configure-custom-domain.md

@@ -63,7 +63,7 @@ There are several API Management endpoints to which you can assign a custom doma
 * Only API Management instance owners can use **Management** and **SCM** endpoints internally. These endpoints are less frequently assigned a custom domain name.
 * The **Premium** and **Developer** tiers support setting multiple hostnames for the **Gateway** endpoint.
 * Wildcard domain names, like `*.contoso.com`, are supported in all tiers except the Consumption tier. A specific subdomain certificate (for example, api.contoso.com) would take precedence over a wildcard certificate (*.contoso.com) for requests to api.contoso.com.
-* When configuing a custom domain for the **Developer portal**, you can [enable CORS](enable-cors-developer-portal.md) for the new domain name. This is needed for developer portal visitors to use the interactive console in the API reference pages.
+* When configuring a custom domain for the **Developer portal**, you can [enable CORS](enable-cors-developer-portal.md) for the new domain name. This is needed for developer portal visitors to use the interactive console in the API reference pages.
 
 ## Domain certificate options