title: TYPO3 FlexForm is not appearing
body: <p>This is my code. I don't know where is the mistake? Please refere following code and help me</p>
  
  <pre><code>$pluginSignature = str_replace('_','',$_EXTKEY) . '_rock';
  
  \TYPO3\CMS\Extbase\Utility\ExtensionUtility::registerPlugin( 'Rocktechnolabs.' . $_EXTKEY, 'rock', 'THE FAQS' );
  
  \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addPiFlexFormValue($pluginSignature, 'FILE:EXT:' . $_EXTKEY . '/Configuration/FlexForms/flexform_rock.xml');
  
  in Configuration/FlexForms/flexform_rock.xml
  
  &lt;T3DataStructure&gt;
      &lt;sheets&gt;
          &lt;sDEF&gt;
              &lt;ROOT&gt;
                  &lt;TCEforms&gt;
                      &lt;sheetTitle&gt;Function&lt;/sheetTitle&gt;
                  &lt;/TCEforms&gt;
                  &lt;type&gt;array&lt;/type&gt;
                  &lt;el&gt;
                      &lt;switchableControllerActions&gt;
                          &lt;TCEforms&gt;
                              &lt;label&gt;Select function&lt;/label&gt;
                              &lt;config&gt;
                                  &lt;type&gt;select&lt;/type&gt;
                                  &lt;items&gt;
                                      &lt;numIndex index="0"&gt;
                                          &lt;numIndex index="0"&gt;List&lt;/numIndex&gt;
                                          &lt;numIndex index="1"&gt;Faq-&gt;list&lt;/numIndex&gt;
                                      &lt;/numIndex&gt;
                                      &lt;numIndex index="1"&gt;
                                          &lt;numIndex index="0"&gt;Search&lt;/numIndex&gt;
                                          &lt;numIndex index="1"&gt;Faq-&gt;search&lt;/numIndex&gt;
                                      &lt;/numIndex&gt;
                                  &lt;/items&gt;
                              &lt;/config&gt;
                          &lt;/TCEforms&gt;
                      &lt;/switchableControllerActions&gt;
                  &lt;/el&gt;
              &lt;/ROOT&gt;
          &lt;/sDEF&gt;
      &lt;/sheets&gt;
  &lt;/T3DataStructure&gt;
  </code></pre>
  
  <p>I tried a lot but i am not getting flexform during select plugin. Can you help me to find out the mistake?</p>