Factory built extensions are only available for specific revision numbers corresponding to the commit used for the nightly build of extensions each night. However since you have built Slicer from source you cannot expect factory built extensions to appropriately work due to ABI compatibility issues. Therefore you should build the extensions you need from source as well. As a reminder you don’t generally need to build Slicer or extensions from source if they are Slicer scripted loadable modules which are written in python.
How to build extensions from source:
https://slicer.readthedocs.io/en/latest/developer_guide/extensions.html#build-an-extension