Http request configuration url must be a string. Received: {0}
This error occurs when the request configuration parameter passed to the $http service is not an object. $http expects a single parameter, the request configuration object, but received a parameter that was not an object. The error message should provide additional context such as the actual value of the parameter that was received. If you passed a string parameter, perhaps you meant to call one of the shorthand methods on $http such as $http.get(…), etc.
To resolve this error, make sure you pass a valid request configuration object to $http.
For more information, see the $http service API documentation.