On the TMF637 API CTK test the billingAccount is mandatory.
var requiredAttributes = ['billingAccount', 'href', 'id', 'productCharacteristic', 'productOffering', 'relatedParty', 'status'];
According to the conformance documentation it is only mandatory in this scenario: Must be managed when recurring charge are linked to this product.
Can we return dummy values for the billingAccount ?
This looks like a defect to me, Elzahn.
I'll try to engage the TMF focals for the CTK.
Thanks for your alertness