If you want to upload the recordings of Reolink cameras to your NAS, please check the following ways.

Applies to: All Reolink cameras except battery-powered ones, Reolink E1, E1 Pro, Reolink Lumus, and the add-on cameras

If your NAS is a regular NAS or a network hard disk, you may use FTP to upload videos to your NAS/hard disk.

 How to set up FTP for Reolink Products

If your NAS is QNAP or Synology, in addition to uploading videos to your QNAP or Synology via FTP server, you may also add the cameras directly to your QNAP or Synology following the below articles. 

How to Add Reolink Cameras to QNAP directly

How to Add Reolink Cameras to Synology Surveillance Station directly

Note: You could add E1 pro to QNAP and Synology, but you could not use FTP to upload E1 Pro's videos to another NAS/hard disk since it doesn't support the FTP function.