The settings for the invoice.
invoice_item_settingsobject<invoice_item_setting>[]Optionalfield_nameenum<invoice_item_field>Optionaldisplay_preferenceobject<display_preference>Optionalinvoice_additional_settingsobject<invoice_additional_setting>[]Optionalfield_nameenum<invoice_additional_settings_field>Optionaldisplay_preferenceobject<display_preference>Optionalinvoice_policy_and_agreement_settingsobject<invoice_policy_and_agreement_setting>[]Optionalfield_nameenum<invoice_policy_and_agreement_settings_field>Optionaldisplay_preferenceobject<display_preference>Optionalinvoice_details_settingsobject<invoice_details_setting>[]Optionalfield_nameenum<invoice_details_settings_field>Optionaldisplay_preferenceobject<display_preference>Optional