Hi,
Thank you for posting the question to Q&A forum.
Windows offers four container base images that users can build from. If Windows Server Insider and Windows Server core images cannot meet your requirement, please kindly check if the Windows base image or Nano Server image is suitable for you.
Also, I found below article "Windows Server 2019 Now Available" that describes how to pull the new Windows Server 2019 images. Please kindly read it and see if there is any useful information for you.
https://techcommunity.microsoft.com/t5/containers/windows-server-2019-now-available/ba-p/382430
Thanks,
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