Hi,
first you need to use working server like 278 in my case.Download playlist of the video and inside you can see all ts parts of this video starting from 000000.ts - 021830.ts.At the top of playlist you can see info about used key method + uri to the keyfile to decrypt the ts parts.
Code:
https://nlsk3.neulion.com/nlsk3/hls/securekey?id=278&url=/nlds_vod/nfl3/vod/2017/11/26/37403/a81cb5/2_37403_mia_ne_2017_b_whole_1_4500.mp4/19700101000000.m3u8.key
If you use any tools like ffmpeg / streamlink to play the HLS playlist then it will also read and access the link to keyfile what mostly fails because you need to use extra request paramters (referer / cookie etc) like in your case too or you get as answer 403 Forbidden.In this case it also make not much sense only to post the playlist link so with this you cant find out the paramters for the keylink (which you can see in webconsole if you play the stream on the xy pageurl).
Download keyfile,mod the playlist and download the video with ffmpeg.All infos was post already before in some other topics so just check them out again.
greetz