I need add element in a Panel with a button

Can someone help me please?

myDiagram.nodeTemplate =
  $(go.Node, "Auto",  // the whole node panel
    { selectionAdorned: true,
      resizable: true,
      layoutConditions: go.Part.LayoutStandard & ~go.Part.LayoutNodeSized,
      fromSpot: go.Spot.AllSides,
      toSpot: go.Spot.AllSides,
      isShadowed: true,
      shadowColor: "#C5C1AA",

        fromLinkable: true,
        fromLinkableSelfNode: true,
        fromLinkableDuplicates: true,
        toLinkable: true,
        toLinkableSelfNode: true,
        toLinkableDuplicates: true,
        cursor: "pointer"

    new go.Binding("location", "location").makeTwoWay(),
    // define the node's outer shape, which will surround the Table
    $(go.Shape, "Rectangle",
      { fill: lightgrad, stroke: "#756875", strokeWidth: 3 }),
    $(go.Panel, "Table",
      { margin: 8, stretch: go.GraphObject.Fill },
      $(go.RowColumnDefinition, { row: 0, sizing: go.RowColumnDefinition.None }),
      // the table header
          row: 0, alignment: go.Spot.Center,
          margin: new go.Margin(0, 14, 0, 2),  // leave room for Button
          font: "bold 16px sans-serif",
          editable: true, isMultiline: false
        new go.Binding("text", "key").makeTwoWay()),
        new go.Binding("segmentOffset", "segmentOffset", go.Point.parse).makeTwoWay(go.Point.stringify), //Actualitza automaticament les dades al codi
      // the collapse/expand button
      $("PanelExpanderButton", "LIST",  // the name of the element whose visibility this button toggles
        { row: 0, alignment: go.Spot.TopRight }),
      // the list of Panels, each showing an attribute
      $(go.Panel, "Vertical",
          name: "LIST",
          row: 1,
          padding: 3,
          alignment: go.Spot.TopLeft,
          defaultAlignment: go.Spot.Left,
          stretch: go.GraphObject.Horizontal,
          itemTemplate: itemTempl
        new go.Binding("itemArray", "items")),

      { // this tooltip Adornment is shared by all nodes
        $(go.Adornment, "Auto",
          $(go.Shape, { fill: "#FFFFCC" }),
          $(go.TextBlock, { margin: 4 },  // the tooltip shows the result of calling nodeInfo(data)
            new go.Binding("text", "", nodeInfo))
      // this context menu Adornment is shared by all nodes
      contextMenu: partContextMenu

    )  // end Table Panel

Can you please state what you want and how it is different from what you have now? There are several panels in the node template that you provided, along with more for the item template and the tooltip and the context menu.

Screenshots and sketches would be helpful.

What happens if you just add what you want to the panel that you want to have the added element?

I need to go to add real-time elements panel. For example to have CategoryID, CategoryName, discription, picture, test1 (Add this) test2 (add this), test3 (add this). The current test url is: http://acme2.udg.edu/quim/bd.php

I need add this with a button, I already know how to do a button but not this add an item

Thank you very much

What’s the problem with adding a Button to the Panel that you want to have a button to do something?

I do not know how to call the function and What function should I use?

You need to learn about how to construct GraphObjects. Please read: