Hello,
Try to use the IoT Dashboard to download the image of need:
https://learn.microsoft.com/en-us/windows/iot-core/downloads
Download Windows 10 IoT Core from Official Microsoft Download Center
Additionally, for the IoT Core ADK AddonKit, you would generally look for it on GitHub, as it is a community-maintained set of tools and scripts to help create custom Windows 10 IoT Core images. The repository for the ADK AddonKit can be found at:
https://github.com/ms-iot/iot-adk-addonkit
Best Regards,
Hania Lian
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