After creating the chart in Google Sheet, you may need to add the data labels in the charts. For example, to add the values in a line chart.
Step 1: Double-check the chart you created in Google Chart;
Step 2: In the "Chart editor" panel, click the "Series" command;
Step 3: In the "Series" tab, move down and check the box of "Data labels";
Step 4: You will see the data labels on the chart now;
Step 5: If the labels are two close, you can select the series and adjust the series label position;
Step 6: Repeat to adjust the data labels in each series if necessary.