If the game crashes, there should be a popup window with an option to add a note and send the crash information. In-game errors do not trigger any kind of automated report function, though. There may be some information included in the gameplay data if you agree to upload it, but that would very likely never be noticed when analyzing the collective data.
You can email a save to supportdos2@larian.com, with a description or link to this topic (or provide a Dropbox or Google drive link, etc).
Each save is a folder in the '..\Documents\Larian Studios\Divinity Original Sin 2\PlayerProfiles\<ProfileName>\Savegames' folder. In Windows Explorer you can zip file(s) and folder(s) by right clicking on it/them and selecting 'Send To | Compressed (zipper) Folder'.
