If you have no other network option, you could build a custom installer with the required openSUSE package pre-installeed for your driver. We are likely just missing the firmware required for your driver.
Take a look at for example the following pull request which I think is after we have last released our installers as we are due to build fresh ones now we have our latest 4.6.1-0 stable release out:
The main thing to establish is what openSUSE package provides what you need to get your network card functioning as expected. Let us know if you establish what is needed. You may well find that just building with what we have now in the repository will work for you as I think it has progressed since our last installer builds. Just read the README.md in that repo and go the boxbuild method on a suitably capable machines (VM or othewise) and you should end up with a fresh installer with all updates pre-installed. Go with a Leap 15.4 profile for now.
We may, before the next installer build, add all the kernel firmware packages, or some more of the likely candidates anyway.