I have made the chat feature on the map require a login. You do not need to register to view it, just to chat.

To register:
1. Log into the game, and run the command '/dynmap webregister'
a. This will generate a one time use registration code that you will need. It will look like this: 1234-5678
2. Open a web browser, and browse to:
3. Enter your username and password and the registration code that was given to you, and click register.

That should be it. You are then registered to chat through the map.

I have set the scrollback option to 100, which means it will save the past 100 lines of text. This will only show chat after you login though, it does not have a history.

As always, let me know if you have any issues.