For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mistificator/openSUSE_Tumbleweed/home:mistificator.repo
zypper refresh
zypper install zbar
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mistificator/15.6/home:mistificator.repo
zypper refresh
zypper install zbar
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:mistificator/15.5/home:mistificator.repo
zypper refresh
zypper install zbar