Under Security Settings, select API Credentials & Keys.
Based on the need and integration, select New Transaction Key or New Signature Key.
To disable the old Transaction or Signature Key, check the box labeled Disable Old Transaction/Signature Key Immediately.
If the Disable Old Transaction/Signature Key check box is not selected, the old Transaction or Signature Key will automatically expire in 24 hours. This will also impact any use of the Signature Key for transaction response validation for the SHA2 field. If the old Transaction/Signature Key is not expired, the previous key will continue to be used for the hash/response validation.