How to create a bar chart/histogram
This visualization option is available for either a single variable, or a collection of variables.
Hover over either the name of a single variable, or over the name of a variable collection. Click on the bar chart icon.
Click on the Options button next to the bar chart visualization.
Configure the bar chart options as desired and click "Update", or "Save As" to save it as a new style.
Be aware that when you use update, all bar charts that use the same style will use the new updated style as well. >> More on styles.