Series.Line - Using the Data Labels Element
A "data label" is text shown next to each data point that shows its value. When the Data Labels element is used as a child of Series.Line, text representing the data values will appear on the chart:
The Data Labels element has attributes that allow you to control the font family, color, size, and weight, the data format, border color, and positioning of the text. The Data Labels element's color-related attribute values can be set using @Chart tokens.