If you are playing on PC, please email supportdos2@larian.com with your save (or a Dropbox or Google drive link, etc). If you are using any mods, also include a list of those enabled and/or the modsettings.lsx from your profile folder.
Each save is a folder in the '..\Documents\Larian Studios\Divinity Original Sin 2 Definitive Edition\PlayerProfiles\<ProfileName>\Savegames\Story' folder.
In Windows Explorer you can zip a file or folder by right clicking on it/them and selecting 'Send To | Compressed (zipped) Folder'.
PS4 saves can be sent, as well, but they would need to be transferred to a USB flash drive first.
In the Saved Data in System Storage section of the Settings menu, click Copy to USB Storage Device, select the save and Copy. From there you can zip the files, then copy to email or upload somewhere and provide a link.