Share JSXGraph: example "3D ruled surface: Möbius strip"

<div id="board-0-wrapper" class="jxgbox-wrapper " style="width: 100%; ">
   <div id="board-0" class="jxgbox" style="aspect-ratio: 1 / 1; width: 100%;" data-ar="1 / 1"></div>
</div>

<script type = "text/javascript"> 
    /*
    This example is licensed under a 
    Creative Commons Attribution ShareAlike 4.0 International License.
    https://creativecommons.org/licenses/by-sa/4.0/
    
    Please note that you have to mention 
    The Center of Mobile Learning with Digital Technology
    in the credits.
    */
    
    const BOARDID = 'board-0';

    var board = JXG.JSXGraph.initBoard(BOARDID, {
        boundingbox: [-8, 8, 8, -8],
        keepaspectratio: false,
        axis: false
    });
    
    var view = board.create('view3d',
        [
            [-6, -3],
            [8, 8],
            [
                [-5, 5],
                [-5, 5],
                [-5, 5]
            ]
        ], {
            xPlaneRear: {
                visible: false
            },
            yPlaneRear: {
                visible: false
            },
            zPlaneRear: {
                fillColor: 'blue'
            }
        });
    
    var r = board.create('slider', [
        [-7, -6],
        [5, -6],
        [1, 3, 5]
    ], {
        name: 'r'
    });
    var c = view.create('parametricsurface3d', [
        (u, v) => r.Value() * (Math.cos(2 * u) + v * Math.cos(u) * Math.cos(2 * u)),
        (u, v) => r.Value() * (Math.sin(2 * u) + v * Math.cos(u) * Math.sin(2 * u)),
        (u, v) => 0 + 2 * v * Math.sin(u),
        [0, Math.PI],
        [-0.5, 0.5]
    ], {
        strokeColor: 'red',
        strokeWidth: 1,
        strokeOpacity: 0.9,
        stepsU: 50,
        stepsV: 1
    });
 </script> 

<jsxgraph width="100%" aspect-ratio="1 / 1" title="3D ruled surface: Möbius strip" description="This construction was copied from JSXGraph examples database: http://jsxgraph.org/share/" useGlobalJS="false">
   /*
   This example is licensed under a 
   Creative Commons Attribution ShareAlike 4.0 International License.
   https://creativecommons.org/licenses/by-sa/4.0/
   
   Please note that you have to mention 
   The Center of Mobile Learning with Digital Technology
   in the credits.
   */
   
   var board = JXG.JSXGraph.initBoard(BOARDID, {
       boundingbox: [-8, 8, 8, -8],
       keepaspectratio: false,
       axis: false
   });
   
   var view = board.create('view3d',
       [
           [-6, -3],
           [8, 8],
           [
               [-5, 5],
               [-5, 5],
               [-5, 5]
           ]
       ], {
           xPlaneRear: {
               visible: false
           },
           yPlaneRear: {
               visible: false
           },
           zPlaneRear: {
               fillColor: 'blue'
           }
       });
   
   var r = board.create('slider', [
       [-7, -6],
       [5, -6],
       [1, 3, 5]
   ], {
       name: 'r'
   });
   var c = view.create('parametricsurface3d', [
       (u, v) => r.Value() * (Math.cos(2 * u) + v * Math.cos(u) * Math.cos(2 * u)),
       (u, v) => r.Value() * (Math.sin(2 * u) + v * Math.cos(u) * Math.sin(2 * u)),
       (u, v) => 0 + 2 * v * Math.sin(u),
       [0, Math.PI],
       [-0.5, 0.5]
   ], {
       strokeColor: 'red',
       strokeWidth: 1,
       strokeOpacity: 0.9,
       stepsU: 50,
       stepsV: 1
   });
</jsxgraph>