How to pass JSON dictionary as parameter using JSON Model by Post method?

I want to pass a JSON dictionary as a parameter by using uploadUrl, but it gives me an Unsupported Url error with code-1002.

When I hit this URL on Postman, it works perfectly. How do I implement this using a JSON model?

NSString *uploadUrl =@"<Your host URL>";

[JSONHTTPClient postJSONFromURLWithString:uploadUrl params:nil
                               completion:^(NSDictionary *json, JSONModelError *err)
{
    if(err == nil)
    {
        UIAlertView *alert=[[UIAlertView alloc]initWithTitle:@"success" message:@"uploaded" delegate:self cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
        [alert show];
        completionHanldler(json);
    }
    else
    {
        UIAlertView *alert=[[UIAlertView alloc]initWithTitle:@"Failed" message:@"uploaded" delegate:self cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
        [alert show];

        NSMutableDictionary *errorDict=[[NSMutableDictionary alloc]init];
        if(err.code==-1009)
            [errorDict setObject:@"The Internet connection appears to be offline."forKey:@"error"];
        else
            [errorDict setObject:@"Error occurred. Please try again!"forKey:@"error"];

        completionHanldler(errorDict);
    }
}];

stringByAddingPercentEscapesUsingEncoding

This method solved this issue. Previously I was assigning the unsupported URL.

NSError * err;
NSData * jsonData = [NSJSONSerialization dataWithJSONObject:parameters options:0 error:&err];
NSString *myString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
// This line is the answer.
myString = [myString stringByAddingPercentEscapesUsingEncoding: NSUTF8StringEncoding];

NSString *uploadUrl = [NSString stringWithFormat:@"<MY host URL>"?data=%@",myString];

[JSONHTTPClient postJSONFromURLWithString:uploadUrl params:nil
                               completion:^(NSDictionary *json, JSONModelError *err)
{
    if(err == nil)
    {
        UIAlertView *alert=[[UIAlertView alloc]initWithTitle:@"success" message:@"uploaded" delegate:self cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
        [alert show];
        completionHanldler(json);
    }
    else
    {
        UIAlertView *alert=[[UIAlertView alloc]initWithTitle:@"Failed" message:@"uploaded" delegate:self cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
        [alert show];

        NSMutableDictionary *errorDict=[[NSMutableDictionary alloc]init];
        if(err.code==-1009)
            [errorDict setObject:@"The Internet connection appears to be offline."forKey:@"error"];
        else
            [errorDict setObject:@"Error occurred. Please try again!"forKey:@"error"];

        completionHanldler(errorDict);
    }
}];