Yes , you can . maybe something like
$reply_data = array(
'ticket_id'=>9,
'vars' => array(
'ticket_id'=>9,
'staff_id' => null, // the reply is from this staff user
'client_id' => 2, // the reply is from this client user
'contact_id' => null, // the reply is from this client contact user
'type' => "reply", // this is a ticket reply
'details' => "API reply", // the ticket reply description
'status' => "open", // status of the ticket
'staff_id' => null, // the staff user the ticket is assigned to
),
'files' => null,
'new_ticket' => false // this reply is for a newly created ticket
);
$response = $api->post("support_manager.support_manager_tickets", "addReply", $reply_data);