The carrier in the payload must be one of the values in the list below for Two Boxes to be able to retrieve tracking information for the return
'amazonlogistics',
'amazoninternational',
'apcpostal',
'apg',
'aramex',
'asendiaus',
'australiapost',
'axlehire',
'bettertrucks',
'borderguru',
'boxberry',
'bring',
'canadapost',
'cdl',
'chronopost',
'colissimo',
'collectplus',
'correiosbr',
'correosespana',
'courierpost',
'couriersplease',
'deutschepost',
'dhlbenelux',
'dhlecommerce',
'dhlexpress',
'dhlgermany',
'dhlgermanyc2c',
'dpd',
'dpdgermany',
'dpduk',
'epostglobal',
'echo',
'estafeta',
'evriuk',
'fastwayaustralia',
'fedex',
'globegistics',
'glsus',
'gophr',
'gso',
'hermesgermanyb2c',
'hermesuk',
'hongkongpost',
'landmark',
'lasership',
'lso',
'maergo',
'mondialrelay',
'newzealandpost',
'nipponexpress',
'notdefined',
'ontrac',
'orangeds',
'pace',
'parcel',
'parcelforce',
'passport',
'passportglobal',
'pcf',
'posteitaliane',
'postennorge',
'posti',
'purolator',
'royalmail',
'rrdonnelley',
'russianpost',
's10',
'sendle',
'skypostal',
'startrack',
'stuart',
'swyft',
'uds',
'ups',
'usps',
'xdelivery',
'yodel',