zrepl source releases are signed & tagged by the author in the git repository. Your OS vendor may provide binary packages of zrepl through the package manager. Additionally, binary releases are provided on GitHub. The following list may be incomplete, feel free to submit a PR with an update:

OS / Distro Install Command Link
FreeBSD pkg install zrepl

FreeBSD Jail With iocage

FreeNAS   FreeBSD Jail With iocage
MacOS brew install zrepl Available on homebrew
Arch Linux yay install zrepl Available on AUR
Fedora, CentOS, RHEL, OpenSUSE dnf install zrepl RPM repository config
Debian + Ubuntu apt install zrepl APT repository config
OmniOS pkg install zrepl Available since r151030
Void Linux xbps-install zrepl Available since a88a2a4
Others   Use binary releases or build from source.