Switch boot JDK
PyCharm includes JetBrains Runtime (based on OpenJDK 11), which is used by default. It is recommended to run PyCharm 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 PyCharm
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 PyCharm 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 pycharm.jdk file in the PyCharm 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 PyCharm by adding the PYCHARM_JDK environment variable with the path to the desired JDK home directory.