Informative Jottings

curl --silent "$id" | jq -r '.results[0].feedUrl'

The above should work on Linux and MacOS. You may need to install jq.

The id is at the end of the url. For example, has id 73801817.

This method is known to be working in the year 2019.

Advanced one-line version using the original url (requires grep):

URL= &&  curl --silent "$(echo $URL | grep -E -o "[0-9]{4,}")" | jq -r '.results[0].feedUrl'