You can delete an already taken screenshot of a heatmap by navigating to a heatmap and scrolling to the bottom of the page. If the heatmap is still active and you have at least write access, then you will be able to delete the screenshot.
The screenshot will be retaken in the near future as soon as a visitor views the page again.
If the heatmap is no longer active, it is not possible to delete the screenshot because the screenshot would not be retaken.
Alternatively, there are also API methods (
HeatmapSessionRecording.deleteHeatmapScreenshot) and Console commands (
heatmapsessionrecording:remove-heatmap-screenshot) available to remove a screenshot.