Moz offer API access to both free and paid accounts, so if you haven’t got one already, go and create an account. If you have a paid account you have better access which means you can request more data, more quickly.
Head over to their API page to generate your API credentials.
Hit ‘Generate Secret Key’ and it will generate you an Access ID and a Secret Key, which you then need to enter into the Account Settings on URL Profiler.
Hit the 'Test' button to make sure your account connects ok (you should get a 'Success' response).