Hi karencaones,
Thank you for reaching Microsoft Community.
I'm sorry to hear about what happened to your original Surface Laptop 3. I assume by recovery key, you meant the BitLocker Recovery key. Bitlocker feature is just for security purposes (drive encryption) on our devices and not for saving/backing up files. See this page for more details on Bitlocker Device Encryption in Windows 10.
If you have set up and synced OneDrive on your original device, you may recover the files by signing in also to the same Microsoft Account on the replacement Surface Laptop 3. See this page for details: What is OneDrive/Backup files using OneDrive. Other than using Onedrive, I'm sorry but there is no other way we could recover from your original Surface.