Currently, it's required for you to see much of your competitor metrics (eg. MozRank, Domain Authority, Page Authority).
You can obtain it by creating a Moz account here: https://moz.com/products/api/keys.
After you do that, you can generate your free API key: https://monitorbacklinks.com/s/i/screenshot-moz-api-key.png.
Then please update your Moz API key info in your account settings: https://monitorbacklinks.com/app/account/general-settings.