Don´t work with PHP > v.8
TYPO3 11.5, last v. of your ext.
With PHP 7.4 it works, with php > 8 : implode():
Core: Exception handler (WEB): Uncaught TYPO3 Exception: implode(): Argument #2 (closed) ($array) must be of type ?array, string given | TypeError thrown in file /httpdocs/typo3conf/ext/lfeditor/Classes/Service/FileBaseXLFService.php in line 266. Requested URL: /typo3/module/user/LfeditorLfeditor?token=--AnonymizedToken--&tx_lfeditor_user_lfeditorlfeditor%5Baction%5D=generalSave&tx_lfeditor_user_lfeditorlfeditor%5Bcontroller%5D=Generale