The pin is an accession.
DEEDAR_URL names the directory (file:// plus a path). Unset, the command has nowhere to write. deedar create file needs --id, --path, and --agent. The pin is deed-… or sha256:.
ljos evidence asks deedar for the bytes. ljos deed ID --add ACCESSION names the accession on a ticket. It does not paste the product into the ticket. The pack may name the same accession. That is not a merge.
If the store is empty, that is an error.