How to save data in Asp.net MVC when the relationship is many to many?

Question

ASP.NET

Hello.
Please tell me how to save tags for news tags in texbox separated by commas.
There are two tables

public class News
    {       
        public Int64 NewsId { get; set; }

        [DisplayName("Название новости")]
        [Required(ErrorMessage = "Заполните название новости")]
        public string Title { get; set; }

        [DisplayName("Краткое содержание новости")]
        [Required(ErrorMessage = "Заполните краткое содержание")]
        [DataType(DataType.MultilineText)]
        [AllowHtml]
        public string Abstract { get; set; }

        [DisplayName("Новость")]
        [Required(ErrorMessage = "Заполните новость")]
        [DataType(DataType.MultilineText)]
        [AllowHtml]
        public string Body { get; set; }

        [DisplayName("Дата добавления сообщения")]
        [Required(ErrorMessage = "Заполните дату")]
        public DateTimeOffset AddedDate { get; set; }

        [DisplayName("Сообщение одобрено")]        
        public bool IsApproved { get; set; }  

        public virtual ICollection<Tags.Tags> Tags { get; set; }
     
    }

and

public class Tags
    {
        [Key]
        public string Tag { get; set; }       

        [DisplayName("Дата добавления тега")]
        public DateTimeOffset AddedDate { get; set; }      

        public virtual ICollection<News.News> News { get; set; }
    }

and controller

public async Task<ActionResult> Create([Bind(Include = "NewsId,Title,Abstract,Body")] News news)
        {            
            if (ModelState.IsValid)
            {
                news.AddedDate = DateTimeOffset.Now;          
                
                db.News.Add(news);
                await db.SaveChangesAsync();
                return RedirectToAction("Index");
            }

            return View(news);
        }

Answer 1

Figured it all out
myself db.Tags.Find("Nec").News.Add(news);
await db.SaveChangesAsync();