I usually know what the name of the unit file for a service is … but sometimes you just need to ask what’s there. Or search for one that isn’t showing up with the expected name.
linux1505:~ # systemctl list-unit-files | grep zfs
zfs-import-cache.service enabled
zfs-import-scan.service disabled
zfs-import.service masked
zfs-load-key.service masked
zfs-mount.service enabled
zfs-scrub@.service static
zfs-share.service enabled
zfs-volume-wait.service enabled
zfs-zed.service enabled
zfs-import.target enabled
zfs-volumes.target disabled
zfs.target enabled
zfs-scrub-monthly@.timer disabled
zfs-scrub-weekly@.timer disabled