It's simple! Just click on this link to get started https://optimize.me/settings/account
When you're there, enter your desired username, enter your password and click Save Changes. If the username you selected is already taken, you’ll get an error like this one. Simply try again with another username! (Sorry, optimize.me/zak is already locked down! 😉 )
Looking forward to connecting with you in the community of Optimizers!
Zak & the Optimize team