// Get the X axis of bubble chart
var axisX = bubbleChart.getChartArea().getAxisX();
// Clear collection of old labels for the X axis
var labelsCollection = axisX.getLabels();
labelsCollection.rebuild();
// Determine three labels for the X axis
var labelsSettings = {
    IntervalsCount: '2', // Total number of intervals between labels
    Margin: '5 5 5 5', // External label margins
    Chart: bubbleChart, // bubble chart
    VisualType: axisX.getType(), // Type of bubble chart item
    MaskText: "{%Value:#,##.}", // Text mask for labels
    Style: { // Color labels blue
        Release: new PP.Style({
            Font: {
                Color: "#3366FF"
            }
        })
    },
    IsVisible: true,
    Min: 0, // Minimum value
    Max: 300000 // Maximum value
};
// Create collection of labels
var labels = new PP.Ui.ChartLabelCollection(labelsSettings);
// Create and set collection of labels
axisX.setLabels(labels);
// Refresh bubble chart
bubbleChart.refresh();