Securely unsetting variables after form redirect

My question is on security perspective!

I'm collecting highly secured information like card data on a form and doing a form redirection to a gateway page. Is there a way to unset the data before/after the job ?

• php GC does the job, but that's not enough for the security team
• since it's not a cURL and a form redirect, unset() doesn't help, because form will have no payload.
• again, since it's a form redirect, we won't have control over the data once form is redirected.

The payload is prepared on controller and view is called from where form is submitted. I'm looking for a way to securely clear/unset manually the variables/payload prepared on controller after view is called and form is redirected.

Controller:

$data['card_number'] = $request->input('chd');
//Other payload info
return view('form', $data);

View:

<form action ='https://3party.site/resource's>
input type ='text' name ='{{$card-number}}'>
//Other params comes here
</form>

My requirement is to unset the card_number value safely after the form action is done. Although, PHP Garbage collector does the job, security team wants to have better control with assurity that the data would be destroyed.

Background info:

using PHP 7.4 Laravel 7.x