See here (and search for filelist.json) for a method which goes directly to the dlist files for the file info. This is a little harder because you have encryption so your filenames end in .zip.aes and you decrypt using SharpAESCrypt.exe from Duplicati folder, or third-party one like AES Crypt. After that, unzip and get JSON.
Ask as you like. That was just the high-level sketch of it.
I don’t do Powershell, but someone else might help. Ultimately, the question is whether you get it to work…