Hello, @Khubaib Khan,
Thanks for using our Theme and for contacting us.
1.. There is no error on the checkout page. it’s working fine. Here is the video proof for a better reference: https://streamable.com/bs01t7 please watch the video and then check back to your site after clearing the browser cache.
2.. Please try to disable all the third-party plugins (including cache plugins), that do not come bundled with XStore https://xstore.helpscoutdocs.com/article/36-included-plugins clear the cache of the browser, and check then. Maybe one of the additional plugins is the reason for the problem.
And if the issue will still persist then please remain all the third-party plugins deactivated on your site and provide me the login access to your site in the below-listed format in the private content area and allow permission to debug your site which includes deactivating all the third-party plugins and on-site Customization as well so that I will check and assist you accordingly.
WP Admin URL:
WP Admin Username:
WP Admin Password:
Note: Please take the complete backup of your site first.
Regards 8Themes Team.