So far as I know, the opposition doesn't claim that it has raw ballots. It claims that it has mesa-level receipts, which show vote totals for the candidates. It has posted them here:
https://resultadosconvzla.com/
I've been digging into it along with a couple other folks on X:
https://octodon.social/deck/@aspensmonster/112884327977911215
A small sampling of the receipts they've put forward
https://diode.zone/w/dGcCfyH9zPYT8LfpdToDec
shows that only nine percent of these receipts have actual inked signatures or fingerprints from the poll workers. The remainder only have the digital signatures, that are gathered ahead of time, and are used to compare against the actual inked signatures. I.e., it certainly looks like, for most of their receipts, they just asked a voting machine to print out a receipt, and then scanned it and put it on their website. The actually important part, where poll workers validate the results and certify them with their physical signatures on the receipts, is not documented by what the opposition has posted thus far.