Run the script:
ruby hash-generator.rb
Usage: hash-generator [options]
-h, --header HEADER The complete header, including the timestamp and sha256 value.
-f, --file PAYLOAD_FILE The name of the file containing the JSON payload.
-s, --secret SECRET
ruby hash-generator.rb -h "CityBase-Signature: t=2022-02-10T03:50:54Z,sha256=<sha here>" -f payload.json -s <some secret here>