Does the
participants.jsonfile automatically allocate parties to the ledger by thedefault_participant?
No the parties are not allocated automatically.
When working with a ledger with authorization, I’d generally recommend to split your script into two: The first performs the admin operations and only those, e.g., party allocation. You then return the allocated parties and other info in the result type and write out the result via --output-file. This script only needs an admin token. Then you have a second script which accepts the result of the first one via --input-file and performs per party operations. The docs have an example of that Daml Script — Daml SDK 2.7.6 documentation.
That said, deadline exceeded shouldn’t be caused by auth issues. Can you reproduce your issue against SDK 2.2?