How to use IFormFile property in a model in asp core 2.1 API?

I want to use the same controller action to save data and attachments i.e. profile pictures.

I added a prop to my model resource with IFormFile datatype,

public IFormFile UserAvatarImage { get; set; }

I am using angular for front-end, I add the uploaded file to my model before I post it to the controller,

My controller model validation keeps giving me invalid input for UserAvatarImage property. I know its a Json.NET deserialization error.

I tried to work around it as mentioned here, using model binding but did not work either,

I also tried to change the property from IFormFile to object and then using file stream reader but did not work too,

var file = model.UserAvatarImage as IFormFile;
string fileContent = null;
using (var reader = new StreamReader (file.OpenReadStream ())) {
       fileContent = reader.ReadToEnd ();
}
var result = JsonConvert.DeserializeObject<IFormFile> (fileContent); 

any other suggestion?