Hello, Plengsak,
Thank you for contacting us and for using XStore.
Registration functionality comes from WooCommerce plugin, so read this article, please – https://woocommerce.com/document/configuring-woocommerce-settings/#accounts-and-privacy-settings
If you have any additional questions or concerns, please do not hesitate to reach out to us. Our support team is always available to assist you.
Kind Regards, 8theme team
