The generated fingerprint:
{{hmac}}
Verify that you are using the current transaction key.
Obtain a new transaction key in the Merchant Interface and update all scripts that require a transaction key accordingly.
Please note that once a new transaction key has been obtained, the old transaction key will expire and become invalid after 24 hours. Be sure that all sites using SIM are updated with the new transaction key before the old key expires.
To obtain a transaction key:
Remember to store the transaction key in a secure location. Do not share it with anyone, as it is used to protect your transactions.