Time series charts

After developing this code:

var dataset = ee.ImageCollection("ECMWF/ERA5_LAND/HOURLY").select("temperature_2m");



// Change de user interface to put into pannels de differences selection
// Create User Interface portion 
// Create a panel to hold our widgets.
var panel = ui.Panel();
panel.style().set('width', '300px');
// Create an intro panel with labels.
var intro = ui.Panel([
  ui.Label({
    value: 'Chart Inspector',
    style: {fontSize: '20px', fontWeight: 'bold'}
  }),
  ui.Label('Click a point on the map to inspect.')
]);
panel.add(intro);

// panels to hold lon/lat values
var lon = ui.Label();
var lat = ui.Label();
panel.add(ui.Panel([lon, lat], ui.Panel.Layout.flow('horizontal')));

// Register a callback on the default map to be invoked when the map is clicked
Map.onClick(function(coords) {
  // Update the lon/lat panel with values from the click event.
  lon.setValue('lon: ' + coords.lon.toFixed(2)),
  lat.setValue('lat: ' + coords.lat.toFixed(2));
  var point = ee.Geometry.Point(coords.lon, coords.lat);
  //Add the time series plots to the panels
   // Create first chart.
  var TChart = ui.Chart.image.series(dataset, point,ee.Reducer.max(), 360);
  TChart.setOptions({
    title: 'Maximum temperature per month (1981-2020)',
    vAxis: {title: 'Temperature (K)'},
    hAxis: {title: 'date', format: 'MM-YY', gridlines: {count: 30}},
  });
  panel.widgets().set(2, TChart);
  // Create second chart.
  var MinChart = ui.Chart.image.series((dataset, point,ee.Reducer.min(), 360));
  MinChart.setOptions({
    title: 'Minimum temperature per month (1981-2020)',
    vAxis: {title: 'Temperature (K)'},
    hAxis: {title: 'date', format: 'MM-YY', gridlines: {count: 30}},
  });
  panel.widgets().set(3, MinChart);
});
Map.style().set('cursor', 'crosshair');

// Add the panel to the ui.root.
ui.root.insert(0, panel);

var visualization = {
  bands: ['temperature_2m'],
  min: 250.0,
  max: 320.0,
  palette: [
    "#000080","#0000D9","#4000FF","#8000FF","#0080FF","#00FFFF",
    "#00FF80","#80FF00","#DAFF00","#FFFF00","#FFF500","#FFDA00",
    "#FFB000","#FFA400","#FF4F00","#FF2500","#FF0A00","#FF00FF",
  ]
};

Map.addLayer(dataset.median(),visualization)

GEE always find an error that I cannot identify :

Missing required arguments to function series(): region in <global>, line 35