I downloaded webvi examples from https://github.com/ni/webvi-examples. The project files are with extension lvproject . I changed the name to lvproj but I was still not able to open it. The file is reported as corrupted.
If you want to open those, you'll need NXG instead of 2020.
Apparently at some point in the future (I have no idea when, but it was one of the most popular things about NXG) the web module will make its way back to LabVIEW <year number here>, but for now it's not possible.