sdbootutil from devel:microos:systemd-boot project
Select Your Operating System
Add repository and install manually
For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:microos:systemd-boot/openSUSE_Tumbleweed/devel:microos:systemd-boot.repo zypper refresh zypper install sdbootutil