I-TASSER does not find Java

Hi!

I am trying to run the standalone I-TASSER suite in a HPC cluster. Java is installed (OpenJDK Runtime Environment (build 1.8.0_161-b14)) and supposed to be located in /usr/bin/java (at least that is what I got from "which java" command). However, when I run I-TASSER, I constantly receive this error:

Error: /usr/bin/java does not exist.
Please check if -java_home was correct

Moreover, in the error log I have:
which: no java in (/usr/lib64/qt-3.3/bin:/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/opt/ibutils/bin:/home/myuser/.local/bin:/home/myuser/bin).

What I am doing wrong? I know Java is there... Is there something I can do for fixing it?

Thank you very much in advance for your help. Have a nice day!