First, follow this link to:
https://app.datatrics.com/integrations/ticketmatic/ and click on "install"
You will now see the following prompt:
You will have to fill in your account code, access key, and secret key. You can read more about that here.
You can find the account code and access keys on the details page of your application. To obtain API keys, you can send an email to firstname.lastname@example.org