grub2 from home:michael-chang:devel:grub:appendedsig-2.11:v2 project
Select Your Operating System
Add repository and install manually
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:michael-chang:devel:grub:appendedsig-2.11:v2/15.4/home:michael-chang:devel:grub:appendedsig-2.11:v2.repo zypper refresh zypper install grub2