CSRF protection issue

I have added a MailChimp embedded form on my company website. When I scan the website through Acunetix, I found a vulnerabilities issue ‘HTML form without CSRF protection’. How can I add csrf form protection to the embedded form?

Alert: HTML form without CSRF protection
Page URL: https://imerit.net/blog/

I know this is not a WordPress issue, but if someone helps me, I will grateful.

The page I need help with: [log in to see the link]