JSFiddle - React, Tailwind, and code Playground

HTML

<div>
    
  <asp:Checkbox id="stopGeneralNumber" class="cbStopReason" runat="Server" />
    <asp:Button id="deleteselecteditems"  runat="Server"/>
</div>

JavaScript

$('#stopGeneralNumber').on('change', function () {
    if ($(this).prop('checked')) {
        alert("now checked");
        $(this).nextAll("deleteselecteditems").removeAttr("disabled");
    } else {
        alert("now un checked");
        $(this).nextAll("deleteselecteditems").attr("disabled", "disabled"); 
    }
});