Update labels to custom fields

As part of updating labels to custom fields, we'll be introducing changes to the InvoiceLine model of our API:

• labels attribute will point to a migrated custom field called 'Labels',
• New custom_fields attribute will contain a list of all custom fields included in the trip.

As part of this transition, we'll deprecate the labels attribute starting from May 1, 2026.

Please update your automations to use the custom_fields attribute in the coming months to avoid disruptions — and reach out through account managers and support chat in case you have any questions.