curl --request POST \
  --url 'https://scan.sv-1.global.canton.network.sync.global/api/scan/v0/backfilling/updates-before' \
  --header 'Content-Type: application/json' \
  --data '{"migration_id":0,"synchronizer_id":"string","before":"2026-01-01T00:00:00Z","at_or_after":"2026-01-01T00:00:00Z","count":0}'

{
  "transactions": [
    {}
  ]
}