My Php business Logic works perfect on Debug Mode. The output on the terminal is as expected. But after i Deploy the code and make a call using JavaScriptApi the response is empty.
Could you benchmark how long your script execution takes when in the debug mode? If it is more than 5 seconds, the code will not have time to complete the execution in production as the free tier is limited to 5 seconds.
For the moment production business logic available only for Java.
PHP and NodeJs is in our todo list and we currenly working on it.
You can invoke NodeJs scripts through file service as workaround.