Upgrade Windows 10 to 11 Manually
One of my PCs wasn't prompted for Windows 11 upgrade, but upgrade check passed.
Download
Windows 11 Installation Assistant can be downloaded from https://www.microsoft.com/en-au/software-download/windows11.
Install
To trigger manual upgrade, need to download Installation Assistant.
Troubleshooting
Got error when first time ran Installation Assistant. Error code #800070079. Then reboot to fix the issue.
References
How to upgrade a compatible PC to Windows 11 from Windows 10