For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:Ximi1970:branches:devel:languages:nodejs/openSUSE_Tumbleweed/home:Ximi1970:branches:devel:languages:nodejs.repo
zypper refresh
zypper install nodejs20
For 16.0 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:Ximi1970:branches:devel:languages:nodejs/16.0/home:Ximi1970:branches:devel:languages:nodejs.repo
zypper refresh
zypper install nodejs20
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:Ximi1970:branches:devel:languages:nodejs/15.6/home:Ximi1970:branches:devel:languages:nodejs.repo
zypper refresh
zypper install nodejs20