It's not possible (easily) in scripting.
But it's simple, if you use WinSCP .NET assembly (e.g. from a PowerShell script).
https://winscp.net/eng/docs/library_powershell

I am using winSCP to make scheduled backups of a win10 laptop to a Linux computer locally.
For example win10 connects to Linux using the ip 192.168.1.33
To access that computer from everywhere I have a no-ip domain because public ip changes every 12 hours.
I know that if I replace that local ip bye the no-ip domain backups will still work as usual but only if there's internet connection and I have my no-ip account active.
For the cases the laptop works outside the local network, does winSCP have something like alternative connection?
I mean in script.txt set something like "if connection to 192.168.1.33 is unsuccessful then try no-ip".