i have my custom payment method in checkout page with dropdown list. and i want to get that dropdown selected value in knockout js and forward it to controller and store dropdown value in my custom table.

/view/frontend/web/template/payment/custom.html

      <div class="field field-number required">
                <label for="credit_days" class="label">
                    <span><!-- ko i18n: 'Click & Collect Credit Days'--><!-- /ko --></span>
                </label>
                <div class="control">
                    <select id="credit_days"
                            class="credit_days"
                           name="credit_days"
                           data-validate="{required:true}"
            onChange="if(this.value=='requestmore'){document.getElementById('request_more').style.display='block';}else{document.getElementById('request_more').style.display='none';}"
                           data-bind="value:creditDaysSelected(), optionsCaption:'Please chose days...'"
                           >
                        <option value="10days">10 Days</option>
                        <option value="20days">20 Days</option>
                        <option value="30days">30 Days</option>
                        <option value="40days">40 Days</option>
                        <option value="requestmore">Request More Days</option>
                    </select>
                </div>
                <div id="request_more" class="request_more" style="display: none">
                    <label for="request_more_credit_days" class="label">
                        <span></span>
                    </label>
                    <div class="control" id="require_more">
                        <input type="text" data-validate="{required:true}" name="request_more_credit_days" id="request_more_credit_days" placeholder="Enter credit Days of your choice" required>
                        <button type="submit" class="button primary action"> <span translate="'Submit Request'"/> </button>
                    </div>
                </div>
            </div>

I want to store dropdown selected value to my custom db table on click of button using controller.

Any help will be appreciated. Thanks in advance