What Checksum algorithm is used when you export your photos using privacy.apple.com website?

I exported my images using the privacy.apple.com website and I get a list of folders each with a Photos directory and a Recently deleted directory. The photos directory includes a Photos details.csv file which has all the metadata I want to merge into the files as the files seem to be stripped from the file creation date. However, to make a script for this I need to match the fileChecksum field in this csv with one generated by me as the filename is not going to be reliable assuming I have conflicting names.

The checksums are like this

AVUxzAcFwP8CNcJZEM3stmvG2aOB

AYvCTUvJXKuj7fbA+uFTUa0/Cpfo

AeSFmZcsU7qW/1XGKw6qEFy4Svnk

AXXOtSiyIcWD3hR2SfiWKukUpnaP

AT44eESSh20j7f10Ytfx4n8BVwD1

Anyone know what this format is? I went to ChatGPT and it doesn't appear to follow the typical character format for md5, sha1, or sha2 formats. I even tried to decode it from base64 and nope didn't give me anything useful.