Newbie Question Test URL?

Description

Hi I work in the IT department for a company and a user is stating that he and his team are required to use Rocket Chat for a customer. They have downloaded it to their Windows machines and can launch it. When they enter the url given to them by the customer, there is a message stating that it’s an invalid URL. The end user insists that this is the correct url.

My questions to the group are:

  1. Is there a typical syntax for a chat url?
  2. Is there a test url that I can use to connect with my download version to at least confirm connectivity. I will use this to rule out any firewall rules.

Thanks
Chris