You must configure conda prior to using Navigator with Anaconda Server.
Configuring Navigator to work with Anaconda Server
Anaconda Navigator is a desktop graphical user interface (GUI) included in Anaconda Distribution that allows you to launch applications and easily manage conda packages, environments, and channels without using command-line commands. Navigator can search for packages on anaconda.org or in a local Anaconda repository. It is available for Windows, macOS, and Linux.
Learn how to use Navigator in the Anaconda Navigator guide.