Implement a copy-paste functionality using context menu

i am trying to create a copy-paste feature using context menu as displayed here: https://doc.daypilot.org/scheduler/event-copying/

how do i get the following event to fire?

protected void DayPilotScheduler1_Command(object sender, CommandEventArgs e)
{
  switch (e.Command)
  {
    case "paste":
      DateTime pasteHere = (DateTime) e.Data["start"];
      string id = (string) e.Data["id"];

      // find the event using id
      // create a new database record using the original event properties

      DayPilotScheduler1.DataSource = loadEvents(); // your method, load events from database
      DayPilotScheduler1.DataBind();
      DayPilotScheduler1.UpdateWithMessage("Event copied.");
      break;
  }
}

i have added on my daypilot the following:

ContextMenuSelectionID="DayPilotMenuSelection"

AND

<DayPilot:DayPilotMenu ID="DayPilotMenuSelection" runat="server" CssClassPrefix="menu_default">

<DayPilot:MenuItem Action="JavaScript" JavaScript="if (!copied) { alert('You need to copy an event first.'); return; } dps.commandCallBack('paste', {id:copied, start: e.start});" Text="Paste" />

</DayPilot:DayPilotMenu>

do i need to add something more? like oncontextmenuclick = ….