use REST::Client;
use JSON;
use Data::Dumper;

my $client = REST::Client->new();
$client->POST ('https://api.sixfold.com/v1/companies/296/carrier-shipments/0005360404/allocation','{"type":"vehicle", "vehicle_id":"39257" }',{Authorization => 'Bearer 096dd6e084d5f30fazzz', "Content-type" => 'application/json'}); 
print Dumper($client->responseContent());