Manually download safari update

Thanks - I have two "volumes" on my computer. One with Catalina which I use for everything except one 32 bit application. And one with Mojave so I can use the 32 bit application. It is the Mojave volume which will not do the software updates.

System preferences tells me I have updates available but when I ask it do the updates I get a dialog box which says, "Can't connect to the Apple Software Update server. Make sure you're connected to the internet, and then try again."

The computer is connected to the internet. I don't really need Safari on the Mojave volume but I still would like to solve this issue. I've tried everything I can think of and nothing has worked.

Ideas? Thanks.