Add customer user prompt to woocommerce verification page

Question

Add customer user prompt to woocommerce verification page

I am developing a woocommerce store for ordering food. I am trying to add an input field or a grouped button to allow the client to add delivery tips in the total amount of the check.

Backend: I wrote an action that adds a hint to check based on a percentage (say 10% of the total)

add_action ('woocommerce_cart_calculate_fees', 'calculateTipsPercentage', 10, 1);
function calculateTipsPercentage ($ cart) {

    if (is_admin () &&! defined ('DOING_AJAX'))
        return

    $ total_tax = 0;
    $ carttotal = 0;
    // Get the unformated taxes array
    $ taxes = $ cart-> get_taxes (); 

    // get Tax amount from taxes array
    foreach ($ taxes as $ tax) $ total_tax + = $ tax;



   global $ woocommerce;


   $ percentage = 0.10; // percentage of tips (must be entered by customer)
   $ carttotalamount = ($ woocommerce-> cart-> cart_contents_total + $ woocommerce-> cart-> shipping_total); // Cart total without tax
   $ totalorderwithTax = ($ carttotalamount + $ total_tax); // cart total with tax
   $ extrafee = round ($ totalorderwithTax * $ percentage, 2); // extra fee amount

   $ percetagetoShow = ($ percentage * 100);  

    $ woocommerce-> cart-> add_fee ("Tip ({$ percetagetoShow}%)", $ extrafee, true, '');




}