The Developer's Log extension provides development logging/debugging functionality and a BE module to browse the logs.
This is a 9 LTS compatible version of cobwebch/devlog.
TYPO3 extension for logging calls from the Logging Framework (instead of
GeneralUtility:devLog()) and browsing and searching those entries.
If you want to use the FileWriter please add the following code:
$GLOBALS['TYPO3_CONF_VARS']['LOG']['writerConfiguration'] = [ \TYPO3\CMS\Core\Log\LogLevel::DEBUG => [ 'Devlog\\Devlog\\Writer\\FileWriter' =>  ] ];