To integrate your Vidello profile with MailChimp, first you need to log in to your existing MailChimp account.
1) Go to your profile image > Accounts & Billing
2) Click on "Extras" > "API Keys"
3) Scroll down a little bit and Click on "Create A Key"
4) Write a name for your API Key and click "Generate Key"
5) Now, copy the key and click "Done"
6) Open your Vidello account, click on Integrations > MailChimp > paste your API Key there and click "Save Integration".
That's it ;)