To upload or retrieve large attachments using the Attachment API you may need to
configure the maximum transaction time.
Uploading or retrieving large attachments may take a long time depending on the attachment size
and network speed. By default, if a transaction takes longer than 60 seconds, that transaction is
cancelled and the error Transaction cancelled: maximum execution time
If your integration routinely uploads or retrieves attachments greater than 50MB, increase the
maximum transaction time to prevent transactions from being cancelled. An administrator can set
the Maximum duration value of the REST Attachment API request timeout