Enabling customer registration is a two-part process: first, your templates must be updated to support the customer registration feature, and your changes published; and second, once your templates have been updated, you must manually enable customer registration in Checkout & Registration Manager, and publish your Order Settings.
Merchants using standard Editor 3.0 templates (storetemplate. template) have an automated installation option. Merchants using standard Editor 2.0 templates must manually update their templates prior to enabling customer registration. If you're unsure of what template version your store uses, you can check your template version in Store Editor.
If your store has been designed and is maintained by a developer and uses custom templates, we recommend contacting your developer about installing customer registration.
Learn how to install and enable customer registration for your store: