Error when trying to report a non-existing user

[anoriel]

I have an error when trying to report a non-existing user (not a big bug but anyway...):

Steps to reproduce

Try to report a non-existing account
In my case, the given command thorw this error (admin does not exist in my environment):
sudo -u www-data ./occ usage-report:generate --verbose admin

Expected behaviour

I would expect to have a warning telling me the user does not exist.

Actual behaviour

It throws an exception;

An unhandled exception has been thrown:
TypeError: json_decode(): Argument #1 ($json) must be of type string, bool given in /srv/nextcloud/apps/user_usage_report/lib/Reports/SingleUser.php:215
Stack trace:
#0 /srv/nextcloud/apps/user_usage_report/lib/Reports/SingleUser.php(215): json_decode()
#1 /srv/nextcloud/apps/user_usage_report/lib/Reports/SingleUser.php(69): OCA\UserUsageReport\Reports\SingleUser->getUserDisplayName()
#2 /srv/nextcloud/apps/user_usage_report/lib/Command/Generate.php(130): OCA\UserUsageReport\Reports\SingleUser->printReport()
#3 /srv/nextcloud/3rdparty/symfony/console/Command/Command.php(255): OCA\UserUsageReport\Command\Generate->execute()
#4 /srv/nextcloud/3rdparty/symfony/console/Application.php(1009): Symfony\Component\Console\Command\Command->run()
#5 /srv/nextcloud/3rdparty/symfony/console/Application.php(273): Symfony\Component\Console\Application->doRunCommand()
#6 /srv/nextcloud/3rdparty/symfony/console/Application.php(149): Symfony\Component\Console\Application->doRun()
#7 /srv/nextcloud/lib/private/Console/Application.php(211): Symfony\Component\Console\Application->run()
#8 /srv/nextcloud/console.php(100): OC\Console\Application->run()
#9 /srv/nextcloud/occ(11): require_once('...')
#10 {main}

Server configuration

Operating system: Linux Ubuntu
Web server: Apache
Database: Mysql
PHP version: 8.1
Nextcloud version: 24.0.4