Onebox not working

As far as I can see, someone (perhaps your specialists) tried to update the services on the server.
The mysql service is no longer there.
systemctl status mysql
Unit mysql.service could not be found.
Without a database server, boxing will not work.

No, we haven't updated.

Then ask the hoster who did it:
Here are the connections
adm_vps6 pts/0 195.64.183.42 Tue Nov 17 23:46 - 02:08 (02:22)
reboot system boot 3.10.0-1160.2.2. Tue Nov 17 23:45 - 13:29 (13:43)
adm_vps6 pts/0 195.64.183.42 Tue Nov 17 23:30 - 23:45 (00:15)
reboot system boot 3.10.0-1160.2.2. Tue Nov 17 23:25 - 23:45 (00:20)
adm_vps6 pts/0 195.64.183.42 Tue Nov 17 23:10 - 23:25 (00:14)
here are the commands: (this is just an example, someone did the same thing ...)
367 2020-11-17 23:35:32 yum install MariaDB-server MariaDB-client
368 2020-11-17 23:35:55 yum update
369 2020-11-17 23:36:03 yum search mariadb
370 2020-11-17 23:36:50 yum repolist
371 2020-11-17 23:37:55 yum update
372 2020-11-17 23:38:21 yum update mariadb
373 2020-11-17 23:39:07 joe /etc/yum.repos.d/mariadb.repo
374 2020-11-17 23:39:19 yum install joe
375 2020-11-17 23:39:25 joe /etc/yum.repos.d/mariadb.repo
376 2020-11-17 23:39:50 yum makecache
377 2020-11-17 23:40:08 yum search all
378 2020-11-17 23:40:24 yum search all | grep -i mariadb
379 2020-11-17 23:40:41 cd /etc/yum.repos.d/
380 2020-11-17 23:40:42 ls
381 2020-11-17 23:40:50 joe MariaDB.repo
382 2020-11-17 23:41:09 df -h
383 2020-11-17 23:41:22 cd /var/lib/mysql/
384 2020-11-17 23:41:24 du-sh
385 2020-11-17 23:41:32 service mysql stop
386 2020-11-17 23:41:38 cd..
387 2020-11-17 23:41:51 cp -Rp mysql mysql.rm
388 2020-11-17 23:43:52 yum deinstall mariadb-server
389 2020-11-17 23:44:01 yum remove mariadb-server
390 2020-11-17 23:44:11 yum remove mariadb
391 2020-11-17 23:44:28 joe /etc/yum.repos.d/mariadb.repo
392 2020-11-17 23:44:43 cd /etc/yum.repos.d/
393 2020-11-17 23:44:46 rm MariaDB.repo
394 2020-11-17 23:44:54 yum update
395 2020-11-17 23:45:21 yum install mariadb
396 2020-11-17 23:45:37 reboot
397 2020-11-17 23:47:44 nginx -v
398 2020-11-17 23:48:12 wkhtmltopdf -V
399 2020-11-17 23:48:52 yum install ynoconv
400 2020-11-17 23:48:55 yum install unoconv

Yes, we found it. Indeed, at that time, the hosting provider's employees were updating the server.