Internal Error: directory must be writeable (it is!)

I installed kanboard on Manjaro from AUR and configured nginx. Accessing Kanboard in Firefox I get:

Internal Error: The directory "/usr/share/webapps/kanboard/data" must be writeable by your web server user

I made user http (my nginx and php-fpm user) the owner of /usr/share/webapps/kanboard/ and /etc/webapps/kanboard/and everything inside, restarted nginx and php-fpm, but that doesn’t help.

What should I do?

PHP 8.1.6 (fpm-fcgi), nginx 1.20. Linux 5.10. Trying to use it with SQLite.