VWS and its component add-on VWSaprs is software by Ambient Weather that was created long before (several years) before your current model WS-2902C was out. Even before several predecessors to the WS-2902C. The VWS software has stopped being developed. Meaning that newer weather stations are not support. But this is because back then Ambientweather.net didn't exist. What Ambient decided to do is invest in Ambientweather.net as a replacement for VWS. Now Ambentweather.net doesn't realize all of the capabilities that VWS had. But it does solve the issue of making your weather data available and making it available on the Internet. On that account it succeeds.
Now there are still very many users that want to upload to CWOP. You can accomplish this is several ways with your current hardware. There is a way to do it without additional hardware/software. As BKS97 mentioned you can use AmbientCWOP.com as a conduit service. AmbientCWOP is not owned and operated by Ambient and it is also not operated by CWOP. It is just the work of an individual that created the service to form a bridge in the cloud with your Ambientweather.net data and CWOP. That bridge doesn't happen automatically. You need to set things up using this free service and then you'll be uploading to CWOP.
I mentioned that there are other ways. The method of uploading via AmbientCWOP requires reliance on Ambientweather.net and on AmbientCWOP.com and so if either of these services has an outage (which can and does happen from time to time) then your data suffers an outage too. If you invest in your own additional hardware/software then you could upload directly to CWOP cutting out two hops and the less middle man the less to need to rely on. You could then though argue that investing in hardware/software means that then you'll have to rely on that and for your own support. But managing your own stuff if done right can have great results I feel. So with that I'll name the hardware and software that you should consider as alternatives. The first thing to know is that we need a way to get data from your station. Unfortunately you can't get data from your hardware (yet, but its coming in future firmware). So what you can do is invest in a GW1000 which is of a reasonable expense and that is compatible with your WS-2902C sensors. This GW1000 then is able to communicate with other 3rd party software that you can run on a trusty computer. Better to not use your daily driver computer. The computer will need to run 24/7. For this the best recommendation is the Raspberry Pi. A computer that will run headless (no monitor, no keyboard, no mouse) and take up little space, and consume very little power and be totally silent and it will only cost your about $100 for all the parts needed. The software to then run can be any of the following: Cumulus MX, Meteobridge, Weather-Display, or WeeWX. All of these software support the GW1000. Each of these software has considerable following with many of the users on this and other weather forums. There is ample amount of people to ask questions and get help.