Mailchimp subscription doesn't work….

Hello,
I just configured your plugin on my website.
It looks very promising and I’d like to thank you.
I’d like to use it with Mailchimp. I filled Mailchimp API key and I saw my list. Everything looked perfect until I’ve finish configuration. Popup appears on my website. Everyone can fill their name and email and click “subscribe” button. Unfortunately after clicking there is no confirmation and what is much worse – no subscription. Nothing. The only registered thing is counted view of popup. Could you please take a quick look and let me know what I did wrong ?

https://ww.wp.xz.cn/plugins/popup-by-supsystic/