There is no need to set a [Security Code] in the Splashtop Business app. But if you want more security to protect the computer access, you can enable the Require security code option in the Splashtop Streamer settings.
How can I Disable the security code?
If you forget the security code or want to turn it off, you can do so by opening Streamer on the remote computer, (the computer you want to connect to) and go to the security tab, where you can either change the security code or selecting “no additional password” to disable the security code.
The security code can not be reset remotely.