How to disable Online Mode in a Minecraft Server
Online Mode is a server configuration option whether players will authenticate through Mojang's servers before allowing them to connect to your server. The process to Authenticate accounts verified if they are logged in and lets players access their skins.
1 Login to the Kinetic Panel and stop the server.
2 Head to the Settings Page.

3 Click on the Server Properties tab.

4 Inside of the Search Settings box, type in "Online Mode" and change the "True" to "False".

5 From there, you can start your server with Online Mode being Disabled.
Why would you do this?
Proxies - In some cases, you are going to link Multiple Minecraft Servers together with Bungeecord or Velocity, Disabling Online Mode will be required to link all of the servers together.