After the installation is done, click on MailChimp WD menu item. You will need to provide API Key, which can be created here. Simply press Create Key button from Your API keys section, and it will be generated. Copy the key, paste it in the input of MailChimp WordPress plugin and click Connect to MailChimp.
Choose a List
If you already have lists created on your MailChimp account, you can select one from Choose a list option. Alternatively, you can skip this step and have your list integrated later on.
Choose Form Type
There are four types of forms, which you can use to register your MailChimp subscribers, Embedded, Popup, Topbar and Scrollbox. Select one and press Create Form. You will be redirected to form editor page.
Note, that the data from your MailChimp API, lists and account information is available on MailChimp WDpage. You can switch to another account by clicking Change MailChimp API button and replacing the key.
If you have added a new list to your MailChimp, make sure to hit Renew MailChimp lists button to refresh integrated lists. Furthermore, in case you want to remove MailChimp account data from your site cache, click Clear API Cache button on this page.