The company I started to work for has asked me to fix the Embedded Chat, but I have no experience with Salesforce and can't find an answer to my question so far.

The company has Service Cloud licenses available, but no Chat User license available (there is only one but it's in use and I can't find the user assigned to it).

I want to debug/test providing live support, I mean to turn "Chat with an Expert" on the chat button on the company website visitors just to test the live chat feature.

Is there a way to achieve this wihtout a Chat User license? Maybe via some development or debug mode? Or perhaps through some setup that doesn't require Chat User license at all?