Mailchimp adding to newsletter

I tried to add a connection after a form is filled out that they can opt in to a newsletter from mailchimp.  It's not showing up however.  It's from the Childbirth Class Registration form.

 

Thanks,
Sherilee

Have you tried checking the Opt-in option in the Mailchimp integration? 

Do you mean the Opt-in Email option did not appear when you integrated the form? To resolve the issue, please try removing the integration and re-integrating the form with mailchimp again. You can also try clearing your form cache to see if that helps. How to Clear your Form Cache

Do let us know how it goes.

I have, but when would this be shown? After the thankyou page or in their inbox?
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Hello sherilee,

Please be noted that opt-in option will not sent in their email. It will not be displayed in the thank you message.

Thank you!

So how do they get the option to opt in?
Sent from my iPhone
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They will be sent an email to Opt-in that contains a link to do so.