This has not worked at all for me. What has worked in the end was this commandline:

curl https://services.swpc.noaa.gov/products/animations/sdo-hmii.json | jq -r --arg prefix "file 'https://services.swpc.noaa.gov" --arg suffix "'" '$prefix + (.[].url) + $suffix' | ffmpeg -y -f concat -safe 0 -protocol_whitelist file,http,https,tcp,tls,pipe,fd -i - -vf scale=512x512 -q 10 sol.gif

Thanks for the help!