The tag ‘link rel=canonical’ appears more than once in the document.

Hello,

Thank you for contacting Rank Math and sorry for any inconvenience that might have been caused due to that.

It is likely the amp plugin you are using is generating the second canonical URL. Which AMP Plugin are you using? Could you please ensure AMP module is enabled on Rank math dashboard and if your AMP Plugin has an SEO option, please make sure to select Rank math integration.

We might need to take a closer look at the settings. Please edit the first post on this ticket and include your WP logins in the designated Sensitive Data section.

It is completely secure and only our support staff has access to that section. If you want, you can use the below plugin to generate a temporary login URL to your website and share that with us instead:

https://wordpress.org/plugins/temporary-login-without-password/

You can use the above plugin in conjunction with the WP Security Audit Log to monitor what changes our staff might make on your website (if any):

https://wordpress.org/plugins/wp-security-audit-log/

We really look forward to helping you.