[TYPO3-german] Re: TCA für Backend User anpassen

[Tobias Pfender]

I had a similar problem and solved it with this:
if (TYPO3_MODE === 'BE') {
	$BE_USER = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\TYPO3\CMS\Core\Authentication\BackendUserAuthentication::class);
	$BE_USER->dontSetCookie = true;
	$BE_USER->start();
	if (!$BE_USER ->isAdmin()) {
		
	}
}
Adjust the condition to your needs.

Maybe there is a UserTS solution for your problem, too.