How do I integrate these installed extensions into the EXE installation package?

Operating system:Windows 10
Slicer version:4.13
Expected behavior:
Actual behavior:

Thank you 3D Slicer for providing such a handy medical imaging software. I have trouble downloading extensions due to network problems. How do I integrate these installed extensions into the EXE installation package?

This page describes how to download and install extensions without network connection: Extensions Manager — 3D Slicer documentation

Unfortunately, there is an error in the current extensions manager website that breaks the download button:

Until the problem gets fixed you can go to the web user interface of the extensions server backend and download the extensions you need from there. Extensions for Slicer Preview Releases are in the “draft” folder.