Cannot find FLUKA executable 'fluka'

Dear All,
I had recently installed the latest fluka 4-4.0 on Linux/Ubuntu and I am facing some problem with the execution of flair (Version- 3.3-1) software. The software has installed but, I am unable to execute any runs.
The software returns a query as follows:
Warning: ‘fluka’ do not exist
Please set the correct FLUKA directory in Preferences

w> Warning: Cannot find FLUKA executable ‘fluka’
Please set the correct FLUKA directory in Preferences

Please do suggest how to proceed.

Dear Krish,
in the late Fluka/Flair version, the Fluka directory is configured in Ubuntu PATH setting to “/usr/local/fluka/bin” by default. You can check it using “echo “$PATH”” terminal command.
Aslo, you may check Fluka path settings in the Flair interface. Please go “Flair” tab → “Config” button → “Fluka” menu option and see “Fluka directory” value.
Check if these values are in agreement with your actual Fluka installation directory.
Try also to restart your Terminal and/or operation system.

Kind regards,