anchor.diff:                          <tbody>
                           <tr>
                               <td>Authorization Code :</td>
  -                            <td><%=code%></td>
  +                            <td><%=code%>
  +                            </td>
                           </tr>
                           <tr>
                               <td>Callback URL :</td>
  
positive.code: <h3>WSO2 OAuth2 Playground</h3>
  
  <table>
  <tr>
  <td>
        <% if (accessToken==null && code==null && grantType == null) {
            code_verifier = UUID.randomUUID().toString() + UUID.randomUUID().toString();
            code_verifier = code_verifier.replaceAll("-","");
  
            MessageDigest digest = MessageDigest.getInstance("SHA-256");
            byte[] hash = digest.digest(code_verifier.getBytes(StandardCharsets.US_ASCII));
            code_challenge = new String(Base64.encodeBase64(hash), StandardCharsets.US_ASCII);
              //set the generated code verifier to the current user session
            session.setAttribute(OAuth2Constants.OAUTH2_PKCE_CODE_VERIFIER,code_verifier);
  
        %>
                <div id="loginDiv" class="sign-in-box" width="100%">
                    <% if (error!=null && error.trim().length()>0) {%>
                      <table class="user_pass_table" width="100%">
                        <tr>
                            <td><font color="#CC0000"><%=error%></font></td>
                        </tr>
                      </table>
                     <%} %>
  
                      <form action="oauth2-authorize-user.jsp" id="loginForm" method="post" name="oauthLoginForm">
                          <table class="user_pass_table" width="100%">
                              <tbody>
                            
                              <tr>
                                  <td>Authorization Grant Type : </td>
                                  <td>
                                     <select id="grantType" name="grantType"  onchange ="setVisibility();">
              			              <option value="<%=OAuth2Constants.OAUTH2_GRANT_TYPE_CODE%>" selected="selected">Authorization Code</option>
              			              <option value="<%=OAuth2Constants.OAUTH2_GRANT_TYPE_IMPLICIT%>">Implicit</option>
              		                  <option value="<%=OAuth2Constants.OAUTH2_GRANT_TYPE_CLIENT_CREDENTIALS%>">Client Credentials</option>
                                        <option value="<%=OAuth2Constants.OAUTH2_GRANT_TYPE_RESOURCE_OWNER%>">Resource Owner</option>           			              
          			               </select>                                
                                  </td>
                              </tr>
                            
                              <tr>
                                  <td><label>Client Id : </label></td>
                                  <td><input type="text" id="consumerKey" name="consumerKey" style= "width:350px"></td>
                              </tr>
                              
                              <tr id="clientsecret" style="display:none">
                                  <td><label>Client Secret : </label></td>
                                  <td><input type="password" id="consumerSecret" name="consumerSecret" style= "width:350px">
                                  </td>
                              </tr>
                              
                              <tr id="recownertr" style="display:none">
                                  <td><label>Resource Owner User Name: </label></td>
                                  <td><input type="text" id="recowner" name="recowner" style= "width:350px"></td>
                              </tr>
                              
                              <tr id="recpasswordtr" style="display:none">
                                  <td><label>Resource Owner Password : </label></td>
                                  <td><input type="password" id="recpassword" name="recpassword" style= "width:350px">
                                  </td>
                              </tr>
                             
                              <tr>
                                  <td><label>Scope : </label></td>
                                  <td><input type="text" id="scope" name="scope">
                                  </td>
                              </tr>
  
                          <tr id="callbackurltr">
                              <td><label>Callback URL : </label></td>
  
negative.code:                                        style="width:350px"></td>
                          </tr>
  
                          <tr id="pkceOption">
                              <td>Use PKCE</td>
                              <td><input type="radio" name="use_pkce" value="yes">Yes &nbsp;
                                  <input type="radio" name="use_pkce" value="no" checked>No
                              </td>
                          </tr>
                          <tr id="pkceMethod">
                              <td>PKCE Challenge Method</td>
                              <td><input type="radio" name="code_challenge_method" onchange="togglePKCEMethod()"
                                         value="S256" checked>S256 &nbsp;
                                  <input type="radio" name="code_challenge_method" onchange="togglePKCEMethod()"
                                         value="plain">plain
                              </td>
                          </tr>
                          <tr id="pkceChallenge">
                              <td>PKCE Code Challenge</td>
                              <td><input type="text" style="width: 350px" readonly name="code_challenge"
                                         value="<%=code_challenge%>"></td>
                          </tr>
                          <tr id="pkceVerifier">
                              <td>PKCE Code Verifier [length : <%=code_verifier.length()%>]</td>
                              <td><label><%=code_verifier%>
                              </label></td>
                          </tr>
  
                          <tr>
                              <td colspan="2"><input type="submit" name="authorize" value="Authorize"></td>
                          </tr>
  