Hello, Teo Yu Xuan,
Thank you for contacting us and for using XStore.
We’ve disabled Single Product Builder. Please check now.
If you want to use the Builder (Theme Options > WooCommerce > Single product Builder), add content there, for example – https://prnt.sc/02JP2ZL13cYq
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