After installing an application with cPanel Application manager or CloudLinux Ruby or Python Selector, it can be observed LiteSpeed returns a 503 error page.
LiteSpeed doesn't function automatically with Ruby/Passenger/Python applications. Configuring applications without performing the setup script will result in a 503 error page when accessing the application URL.
Run the Ruby/Python setup script:
Note: This command is a universal script that scans known ruby and python installations to configure them in LiteSpeed Web Server.