We should authenticate MailChimp account before using it. This tool is very sensitive and they are very restricted about spamming and sending bulk emails using wrong methods.
So you should authenticate your account first. For it, you need to verify your domain and use SFP and DKIM records in your cPanel.
In the video I have covered: How to setup campaign in GetResponse, How to create and manage Form, How to use GetResponse forms in the WordPress website and How to find subscribed contacts in GetResponse panel?