To upgrade to the Pro plan, ensure the following conditions are met:
Your website should have a custom domain, not the default myshopify.com domain.
Your website must be live and not protected by a storefront password.
Once these criteria is met, you'll have access to upgrade plans within the app. If you wish to set up the app before your website goes live, you can follow these steps: Disable the storefront password > upgrade the app > and then re-enable the storefront password. However, keep in mind that while your site is password-protected, the app won't be able to apply any SEO improvements to your pages. This approach only allows you to customise your app settings before your site goes live, if you choose to do so.