By default, only administrator and employees are allowed to add shipment. To allow other users to add shipments, copy and paste below codes on your child theme’s functions.php file.
add_filter( 'wpcfe_add_shipment_role', 'custom_add_shipment_role' );
add_filter( 'wpcfe_can_edit_fields_roles', 'custom_add_shipment_role' );
function custom_add_shipment_role( $roles ){
//Allow clients to add shipments
$roles[] = 'wpcargo_client';
//Allow agents to add shipments
$roles[] = 'cargo_agent';
return $roles;
}