To input your contact details within your SquashLevels boxes you need to click on "Add contact details" next to your name:
If you need to change your player details you will need to click on the pink box that says "PLAYER DETAILS". There is an option to change your email address and/or phone number:
Please note that that when using the mobile view you need to press on SHOW CONTACTS in order for you to be able to add your contact details: