Shopify currently offers two choices for the customer account type used on a shop, Customer accounts, and Legacy customer accounts (formerly known as new and classic). New shops are set to the new customer accounts type by default, but this may not be the best choice for everyone.

Legacy customer accounts are built directly into your theme, seamlessly integrating the login, registration, and account experience with the rest of your site. The Helium Customer Fields app was originally designed for use with this account type, and some of the app's features still work best with this option. If your shop does not specifically require using any new Customer accounts features, you may have the best luck using the Customer Fields app with legacy accounts.

The new Customer accounts type offers a passwordless registration and login experience, hosted directly by Shopify. Users can register or login on the site just by entering their email, and an emailed passcode. Shopify now supports Customer account extensions, which means that forms can be added directly to the Customer account pages to allow collecting and editing of custom information. However, note that extensions can only be added to the account pages for after a customer has logged in or registered, the actual login and registration experiences cannot be customized directly.

The new Customer accounts system will automatically replace the theme's default registration page and is not customizable, which means that you cannot install the app's forms directly to this page. You can still use a custom form, but will need to install it onto a different page of the site using our app block or shortcode installation methods, and then provide a link to this page, such as by adding it to the site's navigation menus.

When using the new Customer accounts system, customers can will always be able to register directly by just entering their email and the emailed code, bypassing any forms installed to the theme. Depending on your use case, this may not be a problem, but if it is critical for users to be approved or to specifically fill out the custom form, you may need to implement some sort of site restriction or access control based on a criteria such as having a certain tag, which is only applied when they correctly submit the form.

The normal account activation link in the customer emails for approval or verification will no longer be necessary since the customer does not need to set a password. You may want to edit the account invitation email template to change this link to go to the login page instead, where the customer can input their email address to receive the one-time code to login, or when approving new customers, make sure to select not to send an approval/invitation email at all.