For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:flyos:Zotero/openSUSE_Tumbleweed/home:flyos:Zotero.repo
zypper refresh
zypper install zotero
For openSUSE Slowroll run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:flyos:Zotero/openSUSE_Slowroll/home:flyos:Zotero.repo
zypper refresh
zypper install zotero
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:flyos:Zotero/15.6/home:flyos:Zotero.repo
zypper refresh
zypper install zotero
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:flyos:Zotero/15.5/home:flyos:Zotero.repo
zypper refresh
zypper install zotero