javascript - Tap to copy discount code is not working in cart drawer Shopify

function myFunction() 
      {
        var copyText = document.getElementById("myInput");
        copyText.select();
        copyText.setSelectionRange(0, 99999);
        navigator.clipboard.writeText(copyText.value);
            $(".tooltiptext").show();  
             setTimeout(function() {
                    $('.tooltiptext').fadeOut('fast');
                }, 200);
      }Copy code

 .copy_coupon{position:relative;}
                            .tooltiptext{display: none;
                            position: absolute;
                            background: rgb(0 0 0 / 61%);
                            color: rgb(255, 255, 255);
                            top: -25px;
                            padding: 2px 12px;
                            border-radius: 5px}Copy code

<div class="coupon_container">
       <div class="left_text">
            <strong>FLAT 50% OFF ON FIRST ORDER</strong>
            <small>*Applicable on single units.</small>
          </div>                     
          <button class="coupon_tab" onclick="myFunction()">
            <span class="copy_coupon" > 
                 <small class="tooltiptext">Copied</small>
                 <small>Tap Here to Copy</small>
                  <strong>FIRST50</strong>
            </span>
          </button>  
</div> 

<input type="text" value="FIRST50" id="myInput"  style="width:auto;" >Copy code