If you are enforcing strong passwords, the Anonymous options are not available in the New User Creation wizard. The option to enforce strong passwords is defined for the Site and is then inherited by any Settings Templates in the Site, and then inherited by any users in that Settings Template. Therefore, on a Site with strong passwords enforced and any/all existing Settings Templates inheriting that setting, you would need to either create a new Template (perhaps called Anonymous Users) with the option disabled, or otherwise create the new user, giving it a temporary password, and then explicitly disable that user’s “Enforce strong passwords” option in its Security tab. With the strong password enforcement disabled for that user, you can click Change Password and assign anything you want, including the Anonymous options.