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-forms

CreateForm.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
using System.Web.UI;
using Telerik.Sitefinity.Forms.Model;
using Telerik.Sitefinity.Modules.Forms;

namespace Telerik.Sitefinity.Documentation.CodeSnippets.DevGuide.SitefinityEssentials.Modules.Forms
{
    public partial class FormsSnippets
    {
        public static void CreateForm(Guid formId, string formName, string formTitle, string formSuccessMessage, Dictionary<Control, string> formControls)
        {
            var formManager = FormsManager.GetManager();
            var form = formManager.GetForms().Where(f => f.Id == formId).SingleOrDefault();
            Guid siblingId = Guid.Empty;

            if (form == null)
            {
                form = formManager.CreateForm(formName, formId);

                form.Title = formTitle;
                form.UrlName = Regex.Replace(form.Name.ToLower(), @"[^\w\-\!\$\'\(\)\=\@\d_]+", "-");
                form.SuccessMessage = formSuccessMessage;

                var draft = formManager.EditForm(form.Id);
                var master = formManager.Lifecycle.CheckOut(draft);

                if (master != null)
                {
                    if (formControls != null && formControls.Count > 0)
                    {
                        int controlsCounter = 0;
                        foreach (var control in formControls)
                        {
                            control.Key.ID = string.Format(formName + "_C" + controlsCounter.ToString().PadLeft(3, '0'));
                            controlsCounter++;
                            var formControl = formManager.CreateControl<FormDraftControl>(control.Key, control.Value);

                            formControl.SiblingId = siblingId;
                            formControl.Caption = control.Key.GetType().Name;
                            siblingId = formControl.Id;

                            master.Controls.Add(formControl);
                        }
                    }

                    master = formManager.Lifecycle.CheckIn(master);
                    formManager.Lifecycle.Publish(master);

                    formManager.SaveChanges();
                }
            }
        }
    }
}