For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:jhhudso/openSUSE_Tumbleweed/home:jhhudso.repo
zypper refresh
zypper install python3-escpos
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:jhhudso/15.5/home:jhhudso.repo
zypper refresh
zypper install python3-escpos
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:jhhudso/15.4/home:jhhudso.repo
zypper refresh
zypper install python3-escpos