Carrier

const VTPOST    = 'vtp';
const EMS       = 'ems';
const VNPOST    = 'vnp';
const GHTK      = 'ghtk';
const GHNV3     = 'ghnv3';
const SPX       = 'shopee';
const BEST      = 'best';
const TIKINOW   = 'tikinow';