SharePoint Multiselect Choice field Saving using PnPjs

Hi

 

I want to save multiselect dropdown in sharepoint field. I already referred few results in this site.

Choice values in SharePoint : Test1,Test2,Test3,Test4,Test5.

 

From the custom dropdown choice field user will select multiple values i want to save the data in multiselect choice field in sharepoint list.

 

Now am getting results as

 

$pnp.sp.web.lists.getByTitle("TestList").items.add({

LastModifiedByDisplayName:_DisplayUserName,

LastModifiedByUserId:_CurrentUserID,

LastModifiedOn:_modifiedon

}).then(function(resultdata) {

idvalue = resultdata.data.Id;

ShowMsgaddupdate("Data Saved Successfully", "", "Ok");

 

But am not able to save the item. Its throwing error. could you please help me.