A Microsoft file hosting and synchronization service.
If you emptied the OneDrive Recycle Bin in OneDrive online, then if you do not have a Microsoft 365 subscription, you will not have access to the option to 'Recover My OneDrive' available in OneDrive online.
The only hope you have of recovering the files is to use some 3rd party recovery utility to try to undelete and recover the files on your PC.