Create Flext form
1. Create configuration schema. File path <extension_directory>ConfigurationFlexForms<any_file_name>.xml
2. Let’s create employeeConfigurationFlexFormsListConfigs.xml, the code is given below:
<T3DataStructure>
<sheets>
<sDEF>
<ROOT>
<sheetTitle>
General
</sheetTitle>
<type>array</type>
<el>
<settings.detailPid>
<TCEforms>
<label>Detail Page</label>
<config>
<type>group</type>
<allowed>pages</allowed>
<size>1</size>
<maxitems>1</maxitems>
<minitems>1</minitems>
</config>
</TCEforms>
</settings.detailPid>
</el>
</ROOT>
</sDEF>
</sheets>
</T3DataStructure>
3. Whatever you will write with settings here, for example settings.detailPid, you can get that data in settings, as this is the default variable of TYPO3.
4. The variable detailPid is used here to store the selected detail page for the plugin.
5. The type used here is group, and this type is used when you want to select something, here the requirement is to select the page (select the detail page).
6. Set the min and max limit to allow the page selection. Here it is 1, so only one page can be selected.
7. Save the file. After saving the file, assign the Flexform to the plugin by adding it into the tt_content.php file (employee/Configuration/TCA/Overrides/tt_content.php)