Using plugin - vaadin/intellij-plugin GitHub Wiki
Code formatting
Plugin runs Actions on Save while writing files, it means your default code formatter can be used.
Spotless formatter
By default, Vaadin 24.5 projects downloaded from start.vaadin.com (or created using plugin) are using Spotless formatter.
To make use of formatting on save install IntelliJ Spotless plugin and enable Run spotless
as Action on Save: