While a heatmap is displayed, select [Processing] in the menu bar and then select [Peaks] > [Peak Detection] from the drop down menu.
The Peak Detection dialog appears.
The Peak Detection dialog can also be displayed by clicking the
icon in the toolbar.
Set the parameters.
Click [OK].
Clicking [Test] starts peak detection only in the area currently displayed. You can quickly check if the parameters you have set work as expected.
Peaks are marked in cyan and clusters are marked in green.