How do I create a Production account?

When you have validated your integration in your sandbox account, you can create a production account.
Note: your sandbox account and production account are completely separate. You can sign up for a production account here https://manage.marketplace.taxamo.com/auth.html#self-signup/Taxamo.
You will need to agree to the Terms of Service for production and also provide your credit card details. You will not have access to your production API token until credit card details are provided.