It didn’t work for me

I installed this plugin as it was already updated for the newest WordPress, while other plugins lagged behind and were not tested for the newest WordPress yet. For that reason WordPress showed this plugin on the top left, with a 5 star rating.

However, together with a Woocommerce plugin this plugin showed some warning on the bottom of my live website and wasn’t able to subscribe to Mailchimp and didn’t tell me why. It only told it encountered a technical issue.
For real use of this plugin I would also like a Captcha to prevent my site from sending spam in double opt-in mail to fake subscribers.

I have made a report on the support forum for the first issue.