How to resolve Mailchimp custom integration issues?

Hi,

I am wanting to do a custom integration with Mailchimp so clients that subscribe to our newsletter will link to mail chimp.

it is telling me :

Installation steps

  • Enter your website URL.
  • Choose an audience to connect to your site.
  • Click Get Code.
  • Highlight the code and copy it to your clipboard.
  • In your website’s HTML, paste the code just before the closing tag.
  • After you’re done, return to this page and click Check Connection.

However, I am having issues when entering this in it states :
“Hmm, we’re able to reach your site but we can’t find the mc.js script. Is it possible that your HTML is malformed? Double-check that the script tags are present and the HTML is valid on http://www.buildmenow.com.au and try again.”

We have had the Mailchimp integration on here for a long time however it has accidentally been deleted today. Is there a way this can be undone?

Thank you,

Indu