Switch boot JDK
WebStorm includes JetBrains Runtime (based on OpenJDK 11), which is used by default. It is recommended to run WebStorm using JetBrains Runtime, which fixes various known OpenJDK and Oracle JDK bugs, and provides better performance and stability. But in some cases you may be required to use another Java runtime or a specific version of JetBrains Runtime.
Switch the Java runtime used to run WebStorm
On the Help menu, click Find Action, or press Ctrl+Shift+A.
Find and select the Switch Boot JDK action.
Select the desired JDK and click OK.
By default, the list includes runtimes that WebStorm is able to detect. If you want to use a runtime that was not detected, click 
and specify the location of the desired Java home directory.
The path to the selected runtime is stored in the webstorm.jdk file in the WebStorm configuration directory. To revert to the default JetBrains Runtime, you can delete this file, or modify the path to point to another Java runtime.
You can also override the runtime used for WebStorm by adding the WEBIDE_JDK/WEBIDE_JDK_64 environment variable with the path to the desired JDK home directory.