i want to copy the value

wcff_builder.php

line 1794

$html .= (($_ptype != “wccaf”) ? ‘

• ‘ : ”) . ‘<label class=”wcff-option-wrapper-label”><input type=”checkbox” id=”aaaaaa”‘. $common_attrs .’ value=”‘. esc_attr(trim($key_val[0])) .'” ‘. $attr .’ /> ‘ . esc_attr(trim($key_val[1])) .'</label>’. (($_ptype != “wccaf”) ? ‘

‘ : ”);

Please add your id.

line 2134

if (isset($_SESSION[‘code’])) {
} else {
$html .= ‘<div class=”form-row form-row-wide wcff-checkout-field-container address-field” id=”‘. esc_attr($_meta[“key”]).'” data-priority=”‘ . esc_attr($_meta[“order”]) . ‘”>’.$label.$_html.'</div>’;
}

Since we want to show and hide by conditional branching, please add a hook.

I want to copy the Product Field value on the checkout page

javascript

let check  = document.getElementById('aaa')
check.addEventListener('change', function() {
  if (check.checked == true) {
    document.getElementById("billing_last_name").value = ?????????????;
  }
});

Please lend me your wisdom

See image below

https://www.keizu-studio.com/wp-content/uploads/2022/10/ss001.jpg