Mailchimp Integration Not Working

Hi, I’m using the popup integration for MailChimp. After the user registers as a subscriber (entering email in popup) and receives a success notification, the user is still not added in my Mailchimp list.

It was working when I was using MailPoet before. I just switched to MailChimp around 2 weeks ago and realised that I haven’t been receiving any new subscriber notification since then, so I went on to try the popup myself but it doesn’t seem to work. It’s really a problem as I’ve not had any new signups from the popup for 2 weeks now, which is really odd. Can you help me with this? Thanks. Let me know if you need any information.

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