Are you attempting to install this module on a website application (e.g. PHP script), or is this a WHM plugin you are attempting to install? Note that you should review documentation or obtain support from the third-party application if this is a PHP script that's generating that error.
I am installing the app on website using Cpanel and i thought there might be some permission issue with WHM or server side. Error is "You do not have permissions to access module install and use install function".
That is not a cPanel application. It's a third-party application that's not developed by cPanel. Please consult with the support team for that specific script for assistance with installing their application.