Owncloud8.0.8 API

When I use the API to create a user, I don't know what's the meaning of the url " http://admin:secret@example.com/ocs/v1.php/cloud/users -d userid="Frank" -d password="frankspassword" " for example : the install address of the owncloud is in my own computer ,
localhost/owncloud,if I use the API to create a user ,what's the final url should I write!
and the code I write is like this:
var client = new HttpClient();
string res = await client.GetStringAsync(" http://localhost/owncloud/ocs/v1.php/cloud/users?search=admin");
XmlDocument doc = new XmlDocument();
doc.LoadXml(res);
XmlNodeList xx = doc.GetElementsByTagName("status");
foreach(XmlNode xxnode in xx)
{
Console.WriteLine("status:"+xxnode.InnerText);
}
But when I debug it,it prompts (Unauthorized)。

Closing as a duplicate of

Please avoid creating multiple thread about the very same topic. Especially as the "Desktop File Sync" category is the wrong category for such questions.