How to Mount .ucas and .utoc files for DLC setup (with UseIoStore option enabled)

I’ve read epic’s documentation about setting up ChunkDownloader and I watched their video on youtube, It turned out that chunk downloader doesn’t support the new option of UseIoStore and it cannot mount .ucas and .utoc files except .pak file.
Please if you could help me with this, I was struggling for hours to solve this issue and cannot find any document online for solving this!