https://www.microsoft.com/en-gb/software-download/windows10

uupdump.net

Which calendar are you using???
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Because you don't need to be an Insider to get it, it's also a WIN Update

KB5006738 Windows 10 2004 19041.1320, 20H2 19042.1320, 21H1 19043.1320

And you can run either from within either......

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365 - subscription based (always the latest version)
2021 - one off purchase (less updates)

Somewhere to start

What is Internet Key Exchange (IKE) ? | Security Wiki

Install CAB file in Windows 10

Try here
KB5004296 Windows 10 Insider RP 19043.1149 (21H1) or 19044.1149 (21H2)

19043.1202 will be from Sept 14th the "current" release for 21H1 at present available to "seekers".

If you want 19044.1202 as per the first post in this thread you need to install

KB5003791...

Try this thread
KB5005101 Windows 10 2004 19041.1202, 20H2 19042.1202, 21H1 19043.1202
Cumulative Update Preview - September 1, 2021
Category: Win Update

Just to confirm, I have 4 pc's/laptops on Current Branch (19043.1165) plus 2 others on Insider Dev and Beta channels.

All show ReleaseID as 2009 but DisplayVersion shows 21H1 or 21H2 as expected....

What does "DisplayVersion" show in the same registry key section (HLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion??
This is a section of my current 19043.1165 343383

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As it says "some IT Admins" use releaseID to check OS version - Winver does not.
Winver uses the DisplayVersion entry.
If you have an MS account check your device info in that, even my Win11 PC's...

In the release notes:
Changes the functionality for uploading new activity into Timeline. If you sync your activity history across your devices using your Microsoft account (MSA), you cannot...

You don't need to, just create the package and then hit the link on the download page....
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which is the link I posted above ;)

Why not use the usual source -UUP

List of files for Cumulative Update Preview for Windows 10 Version 21H2 (19044.1147) amd64 - UUP dump

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The above posted files are in a directory called "files"
You should also have the following files when you unzip the download package

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If you had read the selection summary you...

Still here on my 10Home machine,
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EDIT:
has been missing from 10Pro (current branch) devices for many updates
Still on my IP beta channel 10Pro

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I've had no problem downloading it with Firefox, or Edge.

However in Chrome I needed to right click on the correct link in the thread (.msu or .cab) and choose Inspect. to arrive here

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...

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Open BIOS
Use F7 to go advanced
Click settings
Click security
▶Security sub-menu (listed on page 68 of the mobo manual)
Use this menu to set the administrator password and the user password for...

So why are you trying to install an update for a previous build version? which will already be included in your current build,hence the message.

KB5001396 - WIN10 version 1909(OS Build 18363.1533)

https://support.microsoft.com/en-us/account-billing/reset-a-forgotten-microsoft-account-password-eff4f067-5042-c1a3-fe72-b04d60556c37

Clean Up Component Store (WinSxS folder) in Windows 10

How To Clean Up WinSxS Folder To Save Space In Windows 10

Had this same "language problem" plus the .net error - reverted to 21337 and now undated to 21364.1011 without errors.