[manager.requestSerializer setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];

{
    "client_id" = "4cdbc040-657a-4847-b266-7e31d9e2c3d9";
    "client_secret" = "72297c88-4260-4c05-9b05-d28bfb11d10b";
    "device_id" = "1B2A4037-D627-40DD-82FC-99C52917174B";
    "grant_type" = password;
    password = 123456;
    username = 186593;
}.