The documentation portal is undergoing maintenance. During this period, you can't create any new user credentials. If you do, you'll need to recreate the user credential after the maintenance period ends.
In the setup page, enter your contact details and email address. You can select to use your email address as a username.
You will receive a registration email with access details and a link to confirm your account. You must confirm the account within 48 hours or register again.
In the registration email, click the account confirmation access link.