Hello,
Please check this topic – https://www.8theme.com/topic/xstore-403-error-and-the-response-is-not-a-valid-json-response/
and this article – https://elementor.com/help/publish-update-button-not-work/#:~:text=403%20error%20when%20attempting%20to,checked%20with%20your%20hosting%20company.
Regards