Enabling debug in the application server is just a tick box, the full instructions are <a href="http://www.papercut.com/kb/Main/HowToEnableDebugInNG" target="_blank" rel="noopener">here</a>. The default log collection size of 2GB is good enough for most sites but if the problem is rare or the customer has a lot of print queues/embedded devices then feel free to increase that size (go for 4GB).