radzen-blazor/RadzenBlazorDemos/Pages/LineChartDataLabels.razor

@using System.Globalization

<RadzenStack class="rz-p-0 rz-p-md-6 rz-p-lg-12">
    <RadzenChart>
        <RadzenLineSeries Data="@revenue" CategoryProperty="Month" ValueProperty="Revenue" Title="Revenue">
            <RadzenMarkers MarkerType="MarkerType.Circle" />
            <RadzenSeriesDataLabels Formatter="@FormatAsUSD" />
        </RadzenLineSeries>
        <RadzenValueAxis Formatter="@FormatAsUSD" />
    </RadzenChart>
</RadzenStack>

@code {
    class DataItem
    {
        public string Month { get; set; }
        public double Revenue { get; set; }
    }

    string FormatAsUSD(object value)
    {
        return ((double)value).ToString("C0", CultureInfo.CreateSpecificCulture("en-US"));
    }

    DataItem[] revenue = new DataItem[]
    {
        new DataItem { Month = "Jan", Revenue = 234000 },
        new DataItem { Month = "Feb", Revenue = 269000 },
        new DataItem { Month = "Mar", Revenue = 233000 },
        new DataItem { Month = "Apr", Revenue = 244000 },
        new DataItem { Month = "May", Revenue = 214000 },
        new DataItem { Month = "Jun", Revenue = 253000 },
    };
}