If you selected them as a “Managed” customer in Step 4 – so you will manage their Trustd MTD account, then you should press “Sign in as customer” and follow this guide on their behalf to set them up. You can also give the customers’ admin access to their account by pressing “Sign in as customer” and navigating to “Settings” > “User Management”
Otherwise, if they are an “Unmanaged” customer, simply share this guide with them.