Catch the custom message returned from the java application in iflow exception sub process

Hi experts,

In our iflow, there is a place which calls the java application.

If the java application occurs error, it will response http status code(500) and the custom message ("it is custom error message") to our iflow.

I would like to know how to catch the custom message returned from the java application in our iflow exception sub process.

Best regards,

Nyein