If you are missing the "Required parameters Tab" in NWadmin API gateway
Then a solution is at hand!

Thanks To a very kind gentleman by the name of Todd Fatheree here is the

In NWadmin, go to the Groupwise view. Select the API gateway and choose
Properties. You should see the Gateway-Specific Setup tab. Select this
tab and choose the Launch button on the left. It should start a program
called GWSETUP.EXE in your API Gateway folder. The key thing in here for
us was to have a way of setting the Addressing Format, which can be done
from this program."