For SLE 15 SP2 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:python:backports/SLE_15_SP2/devel:languages:python:backports.repo
zypper refresh
zypper install python3-opengl
For SLE 15 SP1 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:python:backports/SLE_15_SP1/devel:languages:python:backports.repo
zypper refresh
zypper install python3-opengl
For SLE 15 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:languages:python:backports/SLE_15/devel:languages:python:backports.repo
zypper refresh
zypper install python3-opengl