Is it possible the return of key? | URI

[Llulian]

Hi! And Thanks for this space. One question!

#EXTM3U
#EXT-X-VERSION:2
## Created with Unified Streaming Platform(version=1.7.25)
#EXT-X-MEDIA-SEQUENCE:1
#EXT-X-TARGETDURATION:10
#USP-X-TIMESTAMP-MAP:MPEGTS=900000,LOCAL=1970-01-01T00:00:00Z
#EXTINF:10, no desc
#EXT-X-KEY:METHOD=AES-128,URI="http://something.e$s$d$c.something/g$e$t$k$e$y",IV=0x00000000000000000000000000000000

I understand that it is necessary to send "something" to the url for the return of the key.

If so, what should I send and how to obtain it?
If not, how can i interpret that?

Thanks for the help.