It makes no sense to automate fingerprint retrieval. It defies the purpose. You should verify that the fingerprint is valid. If you don't, you can pretty much configure WinSCP not to bother with checking fingerprint at all.

It's not clear from your question, if this is about SSH host key or FTP TLS certificate. And if you use scripting or .NET assembly. But in general, it does not really matter.
See also https://winscp.net/eng/docs/faq_hostkey

I have an Excel VBA macro application that invokes WinSCP in batch mode to upload anything from one to a dozen files at a time, invoked manually at irregular intervals. In common with quite a few users, I suspect, the only time I know that the server certificate fingerprint has been renewed is when an upload fails. I then have to open the online WinSCP app, extract the fingerprint via the clipboard, store it in the file the upload code expects to find it in and re-run the upload. Bit of a pain.

Is there any way to write into my VBA a method of finding out before the uploads take place if the fingerprint has changed and if so, update the stored version so the uploads will always use the current value?

I asked an AI bot about this and it produced VBA code that asked WinSCP to report the current fingerprint. It was made clear that if it hadn't changed then it would report a blank. If it had changed than it provided the new one. Now, this may or may not work in practice but I would much rather proceed based on the presence of something rather than the absence of something.

Is there any way, using WinSCP or not, to report the actual current fingerprint value of my site that I can run in a VBA environment?