Hello, @Muhammad Ejaz,
Thanks for your contact.
Could you please share the screenshot of the Add to cart button having an issue? You may use this site to upload and share the screenshot here: https://postimages.org/
And also please share the site WP Admin URL and Credentials with me here in the private content area of this topic, so that I will check it for you and help you out accordingly.
WP Admin URL:
WP Admin Username:
WP Admin Password:
Regards 8Themes Team.