If you want to upload the recordings of Reolink cameras to your NAS, please check the following ways.
Via FTP
If your NAS is a regular NAS or a network hard disk, you may use FTP to upload videos to your NAS/hard disk. Here are 2 instructions of FTP compatible device and FTP setup:
Which Cameras/NVRs Support FTP Uploading
How to set up FTP for Reolink Products
Via 3rd party software
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.
Which Reolink Products Support CGI_RTSP_ONVIF
How to Add Reolink Cameras to QNAP directly
How to Add Reolink Cameras to Synology Surveillance Station directly