@Efff dd
Hi,
Is this server can access you internal network ?
If yes, you may like to deploy WSUS service in internal network and download patch/fixes/service packs from Microsoft website, then set the server acquire update form your internal WSUS server.
If not, then please following the steps blow to acquire update packets from Microsoft Catalog Site:
1.Access Microsoft Catalog (http://catalog.update.microsoft.com/v7/site/Home.aspx)
2.Search keyword “windows server 2019” and you can find all update of windows server 2019.
For your reference:
Patch a Server Core installation
https://learn.microsoft.com/en-us/windows-server/administration/server-core/server-core-servicing
Hope above information can help you.
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