Saving multiple row by foreach

Question

In ASP .NET MVC 5 , I am trying to save multiple rows of permissions by the use of foreach

this is my model:

public class RoleClaims
    {
         
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int id { get; set; }
        public string RoleId { get; set; }
        public string Type { get; set; }
        public string Value { get; set; }
    } 

Then I moved to Context :

public DbSet<RoleClaims> RoleClaims { get; set; }

Then I did migration it works:

/****** Script for SelectTopNRows command from SSMS  ******/
SELECT TOP (1000) [id]
      ,[RoleId]
      ,[Type]
      ,[Value]
  FROM [no].[dbo].[RoleClaims]

,so know I am trying to save 4 permission by the use of foreach so this is my controller:

[HttpPost]
        [ValidateAntiForgeryToken]

        public async Task<IActionResult> Generatepermission(string roleId, string module)
        {//geting id
            var role = await _roleManager.FindByIdAsync(roleId);
            //getting role 
            var claims = await _roleManager.GetClaimsAsync(role);

            var Permssion = new RoleClaims();
            if (ModelState.IsValid)
            {
                try
                {
                    //declare the verible
                    var Permssion1 = "Permissions." + module + ".Create";
                    var Permssion2 = "Permissions." + module + ".View";
                    var Permssion3 = "Permissions." + module + ".Edit";
                    var Permssion4 = "Permissions." + module + ".Delete";

                    //object equal the coming value
                     string[] Permssionarry = { Permssion1 , Permssion2, Permssion3, Permssion4 };

                    foreach (var claim in Permssionarry)
                    {


                        Permssion.Value = claim;
                       
                        Permssion.RoleId = roleId;
                        Permssion.Type = "Permission";
                        _context.Add(Permssion);
                        await _context.SaveChangesAsync();

                    }
                }
                catch (DbUpdateConcurrencyException) {
                    throw;
                }
            }


                    return RedirectToAction("Index");
        }

When I run the code the first Permssion1 is only saved when it reach to Permssion2 it gives me this error:

SqlException: Cannot insert explicit value for identity column in table 'RoleClaims' when IDENTITY_INSERT is set to OFF.

I don't know what is the source of error, can any one help? can I save multiple rows by on click in .net