There are several possibilities how to solve this task.
The Clover Designer uses the bundled JDK by default. If you would like the Designer to use any other one, you can download the Oracle JDK for Mac here
This Java instance is installed to /Library/Java by default.
Please note, that there is two-step configuration necessary in this case.
1. Add new JDK in Preferences/Java/Installed JREs. Check the documentation.
2. Set the Preferences/CloverETL/ETL Runtime/Java Runtime Environment (JRE) to Alternate JRE and choose the new one. Check the documentation.
In Clover Server:
The path to the JDK for the Clover Server is configured in the „[tomcat]/bin/setenv.sh“ file for Unix-like systems or the „[tomcat]/bin/setenv.bat“ for Windows system. Check the documentation.
If you run the Server on the same machine as the Designer, you can set the path to the JDK used by the Designer. If not, copy or download the same JDK and save it in a place where the Clover Server will be able to use it, please.
I hope this helps.