I couldn't figure it out with dmesg, but this worked, but i have no clue what all those numbers mean
root@Cloudron:~# grep "Killed process" /var/log/syslog
Jul 5 11:57:32 v2202211115363206125 kernel: [517559.408274] Memory cgroup out of memory: Killed process 36850 (bundle) total-vm:665380kB, anon-rss:372784kB, file-rss:6456kB, shmem-rss:0kB, UID:1000 pgtables:1276kB oom_score_adj:0