403. That’s an error.

Your client does not have permission to get URL /api/manifest/dash/requiressl/yes/source/youtube/id/85431ae923be6131/itag/0/ei/LkPmXPyEGoeMmLAPwK6E6Ak/playback_host/r5---sn-aigl6ner.googlevideo.com/mm/31%2C26/mn/sn-aigl6ner%2Csn-5hnedn7s/ms/au%2Conr/mv/m/pl/64/hfr/all/as/fmp4_audio_clear%2Cwebm_audio_clear%2Cwebm2_audio_clear%2Cfmp4_sd_hd_clear%2Cwebm2_sd_hd_clear/initcwndbps/312500/mt/1558594257/fvip/2/ip/2a03%3Ab0c0%3A1%3Ad0%3A%3Abda%3A1/ipbits/0/expire/1558615950/sparams/ip%2Cipbits%2Cexpire%2Crequiressl%2Csource%2Cid%2Citag%2Cei%2Cplayback_host%2Cmm%2Cmn%2Cms%2Cmv%2Cpl%2Chfr%2Cas%2Cinitcwndbps/signature/504AD3425D22AB66629E630797705ADD988B53F6.5151A0C205DEE92F8A0F49597209AE22C955E4E7/key/yt8 from this server. That’s all we know.