# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/.*?(https?:[^"]+)(?(?!.*?https?:).*)/$1\n\n/gm;t' <<< "[{\"participants\": [\"minanageh379\", \"xcsadc\"], \"conversation\": [{\"sender\": \"minanageh379\", \"created_at\": \"2019-04-12T12:51:56.560361+00:00\", \"media\": \"https://scontent-lax3-1.cdninstagram.com/vp/edddf95178aca7bf75930ab8698ee45b/5D45203B/t51.2885-15/fr/e15/s1080x1080/55823673_114448266206459_7321604432125975069_n.jpg?_nc_ht=scontent-lax3-1.cdninstagram.com&ig_cache_key=Mjg2ODYwNDMxNzU3OTI1MTE1NTAxNjQ1NTk5MDkwOTMzNzY%3D.2\"}, {\"sender\": \"minanageh379\", \"created_at\": \"2019-04-12T12:51:51.923138+00:00\", \"text\": \"sd\"}, {\"sender\": \"minanageh379\", \"created_at\": \"2019-04-12T12:51:41.689524+00:00\", \"text\": \"sdsa\"}, {\"sender\": \"xcsadc\", \"created_at\": \"2019-04-12T12:50:57.283147+00:00\", \"text\": \"👩❤️💋👩\"}, {\"sender\": \"xcsadc\", \"created_at\": \"2019-04-12T12:39:35.248517+00:00\", \"text\": \"czx\"}, {\"sender\": \"xcsadc\", \"created_at\": \"2019-04-12T12:39:34.352752+00:00\", \"text\": \"dsad\"}, {\"sender\": \"xcsadc\", \"created_at\": \"2019-04-12T12:39:30.889023+00:00\", \"media\": \"https://scontent-lax3-1.cdninstagram.com/vp/e985406d6eac06bb11c2d6052c1821a2/5D508106/t51.2885-15/e15/s640x640/56218099_577906226037731_8663356006073884002_n.jpg?_nc_ht=scontent-lax3-1.cdninstagram.com&ig_cache_key=Mjg2ODYwMjk0MjA1ODQxNzYzNjM1OTI1ODMwMjYzMTExNjg%3D.2\"}, {\"sender\": \"xcsadc\", \"created_at\": \"2019-04-12T12:38:54.823472+00:00\", \"text\": \"hi hi hi\"}, {\"sender\": \"ncccy\", \"created_at\": \"2019-01-28T17:09:29.216184+00:00\", \"media\": \"https://scontent-lax3-1.cdninstagram.com/vp/57c43d748xcasc1abf58c890c5a6df042/5D199AE8/t51.2885-15/e15/p480x480/49913269_2181952555454636_8892094125900591548_n.jpg?_nc_ht=scontent-lax3-1.cdninstagram.com&ig_cache_key=Mjg1NjgsdasdAwNjgxNTk1OTY0OTIwMTA1NTMzNDQ%3D.2\"}, {\"sender\": \"ny\", \"created_at\": \"2017-10-22T20:49:50.042588+00:00\", \"media\": \"https://scontent-lax3-1.cdninstagram.com/vp/19d94ea45c2102a0f7c97838ef546b93/5D14B3C3/t51.2885-15/e15/22708873_149637425772501_5029503881546039296_n.jpg?_nc_ht=scontent-lax3-1.cdninstagram.com&ig_cache_key=Mjc4MzA3MDIyMTI3NDE3Njc3NTQxNTM1NTI2MjQyMjIyMDg%3D.2\"}, {\"sender\": \"xcsadc\", \"created_at\": \"2019-04-12T12:39:35.248517+00:00\", \"text\": \"czx\"}]}]"
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html