SF_10.1, SF_10.2, SF_11.0, SF_11.1, SF_11.2, SF_12.0, SF_12.1, SF_12.2, SF_13.0, SF_13.1, SF_13.2, SF_13.3, SF_14.0, SF_14.1, SF_14.2, SF_14.3 - https://docs.sitefinity.com/for-developers-create-list-items

CreateListItemFluentAPI.cs

using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;
using Telerik.Sitefinity.Lists.Model;
using Telerik.Sitefinity.Workflow;

namespace Telerik.Sitefinity.Documentation.CodeSnippets.DevGuide.SitefinityEssentials.Modules.Lists
{
    public partial class ListsSnippets
    {
        public static Guid CreateListItemFluentAPI(Guid parentListId, string title, string content)
        {
            int count = 0;
            Guid id = Guid.Empty;

            // Check whether the parent list exists
            App.WorkWith().Lists().Where(l => l.Id == parentListId).Count(out count);

            if (count > 0)
            {
                // Get the parent and create the list item
                App.WorkWith().List(parentListId).CreateListItem().Do(listItem =>
                {
                    // Get the Id of the list item
                    id = listItem.Id;

                    // Set the list item properties
                    listItem.Title = title;
                    listItem.Content = content;
                    listItem.Urls.Clear();
                    listItem.UrlName = Regex.Replace(title.ToLower(), @"[^\w\-\!\$\'\(\)\=\@\d_]+", "-");
                    listItem.DateCreated = DateTime.Now;
                }).Publish().SaveChanges();
            }

            return id;
        }
    }
}