By following https://blog.josephscott.org/2011/10/14/timing-details-with-curl/, create curl-format.txt
having following lines:
\n
time_namelookup: %{time_namelookup}\n
time_connect: %{time_connect}\n
time_appconnect: %{time_appconnect}\n
time_pretransfer: %{time_pretransfer}\n
time_redirect: %{time_redirect}\n