To access MXM PRO for Publishers you need to:
Go to Musixmatch Pro;
Click in the top right corner where it says "For Publishers";
Fill in the requested information;
You will receive a confirmation email once your request has been approved. At this point, it will be possible to log into the platform using the same method you registered your submission with (i.e.: Google, Facebook, Apple or email and password). For more information, please contact publishers-support@musixmatch.com.