How do I get ALL cloudflare_email entries via the Partner API?

When I first log into my Partners dashboard I am presented with a list of ALL domains regardless which user is associated with them. Using the API I’d like to get a list of all users then a list of all domains associated with each user. This simple snippet works for a single user and provides all the domains associated with that single user but how would I first get a list of users so I can then loop over all the Cloudflare_email entries to get their domain(s) using something like below?

curl -s \
  -d "act=user_lookup" \
  -d "host_key=$CFKEY" \
  -d "Cloudflare_email=$1" | jq .