To upload your passport style photo for your licence, you will need to login to your account on myAthletics portal using your username (your URN) and your password: https://myathleticsportal.englandathletics.org/Account/Login
Click on My Profile in the top right corner, then Edit on your Personal Details and here you will see a link to Upload New Picture. You must ensure your image is no larger than 100x130 pixels and the file size is under 4MB.