How to pass the value of a text box input field to the value of a radio button in jQuery

function increaseValue() {
  var value=parseInt(document.getElementById('number').value, 10);
  value=isNaN(value) ? 0: value;
  value++;
  document.getElementById('number').value=value;
}

function decreaseValue() {
  var value=parseInt(document.getElementById('number').value, 10);
  value=isNaN(value) ? 0: value;
  value < 1 ? value=1: '';
  value--;
  document.getElementById('number').value=value;
}

<div class="custom-control custom-radio mb-3">
  <input name=“coins” value="1" class="custom-control-input fixed-coin" id="1coin" type="radio">
  <label class="custom-control-label" for="1coin">1 Coin</label>
</div>

<div class="custom-control custom-radio mb-3">
  <input name="coins" value="10" class="custom-control-input fixed-coin" id="10coin" type="radio">
  <label class="custom-control-label" for="10coin">10 Coins</label>
</div>

<div class="custom-control custom-radio mb-3">
  <input name="coins" value="100" class="custom-control-input fixed-coin" id="100coin" type="radio">
  <label class="custom-control-label" for="100coin">100 Coins</label>
</div>

<div class="custom-control custom-radio mb-3">
  <input name="coins" value="0" class="custom-control-input custom-coin" id="custom" type="radio">
  <label class="custom-control-label" for="custom">Custom Coin</label>
</div>

<div class="custom-coin" style="display: none;">

  <div class="value-button" id="decrease" onclick="decreaseValue()" value="Decrease Value">-</div>
  <input type="number" class="custom-count" id="number" value="0" />
  <div class="value-button" id="increase" onclick="increaseValue()" value="Increase Value">+</div>
</div>

<div class="book-button text-center">

  <button class="btn btn-primary" type="submit"> Coin </button>

</div>




<script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script type="text/javascript">
  $(document).ready(function() {
    $("input[class$='custom-coin']").click(function() {
      var trig = $(this).val();

      $("div.custom-coin").show();
    });

    $("input[class$='fixed-coin']").click(function() {
      var trig = $(this).val();

      $("div.custom-coin").hide();

    });
  });
</script>