you should urgently update your PHP to a supported version, recommended is php 8.3 at the moment but updating to 8.4 would do it as well
but one step after another… first of all you can deactivate the password-app because I think it doesn’t work with your php-version. So try getting your server re-running again.
if you can’t access your app-page anymore you can use the commandline to disable the app. something like
cd /PATH/TO/NEXTCLOUD sudo -u www-data php occ app:disable NAME_OF_APP
should do the job.
(it’s all in the manual AND mentioned on the forum several times already)
right afterwards your system shoud be running smoothly again.
then it’s highest time to update your php. there’s a good php-update-script made by someone from the forum… take a look here Php-updater - a script to upgrade php in a safe way
after the successful php-update passwords should run again.