DataContext.cs

using JWTAuth.API.Models;
using Microsoft.EntityFrameworkCore;

namespace JWTAuth.API.Data
{
    public class DataContext : DbContext
    {
        public DataContext(DbContextOptions<DataContext> options) : base(options) {}
        public DbSet<Value> Values { get; set; }
    }
}

Value.cs

namespace JWTAuth.API.Models
{
    public class Value
    {
        public int Id { get; set; }
        public string Name { get; set; }
    }
}