Where to get the drivers that are used in the developer edition of the Dell XPS 13 7390 (Fall 2019)?

I’m trying to install a dual boot Windows 10/Ubuntu 18.04 on my XPS 7390 Developer Edition. Initially Ubuntu 18.04 was installed by Dell. Wifi worked flawlessly on this version. Today I installed Windows and then a dual boot with the standard Ubuntu 18.04 distribution. This worked, but the Wifi-Card was not being identified in this…

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