Hide Button on Codeigniter

btw this is my order status

$data['order_status'] = ['wc-processing'=>'Processing', 'wc-on-hold'=>'On Hold', 'wc-completed'=>'Completed', 'wc-pending'=>'Pending'];

You are passing that from the controller to the view, aren't you?
It's an array of possible order statuses, right?
The table with orders is built up by a foreach {} loop, I guess.
In every iteration you should check the order status of the current record.
If that is 'Completed', don't show the button or disable it.