Configure API key
step-1:
First, log in to your MailChimp account.
step-2:
Click on the profile icon on the right side and then select “Account & billing” from the dropdown menu.

step-3:
Look for the section titled “Extras” and click on it.
In the Extras section, you will find an option for “API keys”. Click on it.

Step:4
On the API keys page, you will see a list of any existing API keys you have created. To create a new API key, click on the “Create New Key” button.

step-5:
Mailchimp will generate a new API key for you. The key will be displayed on the API keys page.
Now click Generate key

step-6
Make sure to copy and securely store the API key as it will be needed to connect your plugin to Mailchimp.

That’s it! You have successfully created an API key in Mailchimp.