How to add product attribute > value > ImageSquaresImage on product create - API plugin(Nop-Templates team)

I'm working with API plugin(nop 4.0) developed by Nop-Templates team. All functionalities working fine, however I'm facing some difficulty to save product attribute value of ImageSquaresImage      

Here is class file of ImageDto

    
[ImageValidation]
public class ImageDto
{
    [JsonProperty("src")]
    public string Src { get; set; }

    [JsonProperty("attachment")]
    public string Attachment { get; set; }

    [JsonIgnore]
    public byte[] Binary { get; set; }

    [JsonIgnore]
    public string MimeType { get; set; }
}

And I have tried with passing image URL with Src as well as attachment on product create, but it is not working at all.

So, the question is: how can we store ImageSquaresImage of product attribute value on product create?