Leave this one to the default value or blank if you are using the public Microsoft Azure cloud. If you are using a private or other Azure cloud service, enter the Blob service endpoint URL for that cloud.
Here is a list of commonly used values:
http://blob.core.chinacloudapi.cn
http://core.cloudapi.de
http://core.usgovcloudapi.net
If you enabled secure transfer for your storage account, be sure to prefix your URL with https
.