<add key="SharePointSIte" value="https://abc.com/sites/ISS/ts/buslead/"/>
<add key="apiList" value="Business Lead QA list"/>
using Microsoft.SharePoint.Client;
ClientContext clientContext = new ClientContext(siteUrl);
SP.List oList = clientContext.Web.Lists.GetByTitle(apiList);
ListItemCreationInformation itemCreateInfo = new ListItemCreationInformation();
ListItem oListItem = oList.AddItem(itemCreateInfo);
oListItem["Title"] = lead.LeadName;
oListItem["City"] = lead.City;
oListItem["Zip_x0020_Code"] = lead.Zip;
oListItem["Address_x0020_1"] = lead.Address1;
// oListItem["Address_x0020_2"] = lead.Address2;
oListItem["Phone_x0020_number"] = lead.UserPhone;
oListItem["Email_x0020_Address"] = lead.UserEmail;
oListItem["Branch_x0020_Code"] = lead.BranchCode;
oListItem["Branch_x0020_Name"] = lead.BranchName;
oListItem["FullName"] = lead.UserFullName;
oListItem["Notes"] = lead.Remark;
oListItem["Business_x0020_contact_x0020_nam"] = lead.LeadContactName;
oListItem["Business_x0020_contact_x0020_add"] = lead.LeadContactPhone;
oListItem["Business_x0020_contact_x0020_cit"] = lead.LeadContactEmail;
oListItem["Business_x0020_contact_x0020_sta"] = lead.LeadAcquisition;
oListItem.Update();
clientContext.ExecuteQuery();