You can change your phone number by going to Account → Profile → Personal details.
Important! You can only change your phone number if the previous one has already been confirmed.
Below, you may find the steps to make this update on your account:
Step 1: enter the new phone number
Step 2: enter your password for confirmation
Step 3: you will receive a validation code to the email address registered on your account, which you will enter on the page
Step 4: enter the code received on the new phone number
If you are unable to update your phone number despite following the steps above, or, if you no longer have access to the email address associated with your game account, please check the bottom of the current page and contact us through the available means of your choice.