Do you have any time to act, to be able to use the teleporter pyramids or a waypoint, get to the stairs, summon something, etc?
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 non-Larian mods, also include a list of those enabled and/or the modsettings.lsx file 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' (and similarly in OSX/Finder).
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 relevant save(s) and Copy. From there you can zip the files, then copy to email or upload somewhere and provide a link.
Unfortunately, in that case a fix could only be done with a game update. On console saves are locked to the account used to start the game when they are made. While a PS4 dev kit can load saves created in other accounts, it will still lock the save to the developer account, so there is no way to return a save that you could use.