You can use curl to download the junos kg directly from junos-softdownloads. You need to 1st find your software and gather the download link
Next, just use the cli "curl" with the -o <filename> option to download the file via the link
If you have a local proxy and if the firewall is not directly attached to the internet make sure to use the -x proxy option with curl and provide the details for the proxy.
example
curl -o junospkg.tgz -x 192.0.1.1:8081 -U kfelix:mypassword -k "https:<download link>
Ken Felix
NSE ( network security expert) and Route/Switching Engineer
kfelix -----a----t---- socpuppets ---dot---com
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