WebAPI Store JSON Data

I made a Web API v2 C# project. I m sending json data to my web api. And Im returning json data. I want to store sended data with postman.

 public Models.Response Post([FromBody]Models.Request value)
        {

            var a_project = value.g_project;
            var a_size= value.g_size;
}

How will I store json data. I want to log my json data