How to update the values of custom radio buttons to the corresponding selection field in an online case form when a radio button is selected?

We can update the custom radio button value to corresponding the select field when we selecting the radio button by using the select field id.

<div class="item">
                                        <input type="radio" class="issue_radio Green" onclick="getSelectedValue()"
                                            name="optradio1" id="Green_issue" stdid="7" value="Misc">
                                        <p class="p_radio fields_font">Misc</p>
                                    </div>
                                    <div class="item">
                                        <input type="radio" class="issue_radio Green" onclick="getSelectedValue()"
                                            name="optradio1" id="Green_issue" stdid="1" value="Problem with an order">
                                        <p class="p_radio fields_font">Problem With an Order</p>
                                    </div>
                                    <div class="item">
                                        <input type="radio" class="issue_radio Green" onclick="getSelectedValue()"
                                            name="optradio1" id="Green_issue" stdid="4" value="Returns and refunds">
                                        <p class="p_radio fields_font">Returns and Refunds</p>
                                    </div>

var matchess = document.querySelectorAll('#Green_issue');
        for (matchh in matchess) {
            matchess[matchh].onchange = function () {
                var array = document.querySelectorAll('#issue option')
                for (var i = 0, len = array.length; i < len; i++) {
                    document.querySelectorAll('#issue option')[i].removeAttribute('selected');
                }
                var selectt = document.querySelectorAll('option[value="' + this.getAttribute("stdid") + '"]')
                if (selectt.length > 0) {
                    document.querySelectorAll('#issue option[value="' + this.getAttribute("stdid") + '"]')[0].setAttribute('selected', true);
                }
            }
        }