How to run API on particular URL via Apache Proxy

I have SaltGUI running on a server. I want to make this gui run on http://example.com/gui via apache proxy running on the same server.

How can I do that?

Now I have the following configuration

<VirtualHost *:80>
  ServerName example.com
  ServerAlias example
  ProxyPreserveHost On
  ProxyRequests Off
  RemoteIPHeader X-Forwarded-For
  RemoteIPHeader X-Real-IP
  RemoteIPHeader Host

  <Location "/">
    ProxyPass http://localhost:3333/
    ProxyPassReverse http://localhost:3333/
  </Location>

</VirtualHost>

but it running on example.com and browser sends all requests to http://example.com