Error in Postman request – deserialization

This is in the POSTMAN request body:

{
    "roles":  
        [
            {
                "role_id": "TEST1",
                "role_name": "Для тестов"
            },
            {
                "role_id": "TEST3",
                "role_name": "Для тестов
            }
        ]
}

Model as it is :

public class Role 
{
    [JsonProperty(PropertyName = "role_id")]
    public string role_id { get; set; }


    [JsonProperty(PropertyName = "role_name")]
    public string role_name { get; set; }

    
}

Controller api-method – an Error appeared in Request

HttpPost("[action]/")]
public ActionResult<UserReply> SetRoleMessage(string message_text, List<Role> roles)
{
               //CODE
}

HERE is Postman results with an Error :

>Solution :

You send in an object with a property "roles" which is an array. But what your controller expects is that you send in an array.

Update your body to

[
    {
        "role_id": "TEST1",
        "role_name": "Для тестов"
    },
    {
        "role_id": "TEST3",
        "role_name": "Для тестов"
    }
]

As a side note, I would also use [FromQuery] and [FromBody] in your controller method to make more clear what is what:

public ActionResult<UserReply> SetRoleMessage([FromQuery] string message_text, [FromBody] List<Role> roles)