With this tool, you can get a small button in your game that when clicked on, takes you to the ManiaExchange page of the current map you are on. If the Map is not on MX, the button will not appear.
Works both for TM2020 and TM2 / SM!
In order to install this correctly, unzip the file in your OpenplanetNext / Openplanet4 folder, so that the files go into the Scripts and Textures folders respectively.
Enjoy!