In the Pro version, when using the External Data Sources addon, you can control the Action Content using templates.

You can use placeholders in the template that will be replaced with the content of that property. This is particularly useful if you’re using external data sources with several properties with data, since you’ll have more information to populate the action content.

Each placeholder should be wrapped in curly brackets and it should be the property name. Example:

{title} and {content} exist by default in your data entry. Other placeholders can be used according to your data source.

You can use HTML code to enhance the content.

In the settings page of the plugin, in the Editing tab you can also change the field type for the tooltip template to be a text area or a rich text editor, to have more freedom to create your action content template.

You can explore this feature to display content from you data sources in a lightbox or outside the map for example.