For Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:fmccarthy:AI:pulsar:java/Tumbleweed/home:fmccarthy:AI:pulsar:java.repo
zypper refresh
zypper install glassfish-servlet-api
For 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:fmccarthy:AI:pulsar:java/15.6/home:fmccarthy:AI:pulsar:java.repo
zypper refresh
zypper install glassfish-servlet-api
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:fmccarthy:AI:pulsar:java/15.4/home:fmccarthy:AI:pulsar:java.repo
zypper refresh
zypper install glassfish-servlet-api