Domains you can "curl" to get your external IP address based on using the name of the common network utilities ipconfig and ifconfig as the domain.

external_ip_websites.txt

Use by running "curl $domain"

IP with no line terminator such as Carriage Return (\x0D) or Line Feed (\x0A):
ifconfig.be
ifconfig.ca
ifconfig.cc
ifconfig.in
ifconfig.me
ifconfig.rest
ifconfig.so

ipconfig.cc

IP with Line Feed (\x0A) terminator:
ifconfig.asia
ifconfig.cl
ifconfig.co
ifconfig.computer
ifconfig.cx
ifconfig.cz
ifconfig.download
ifconfig.ee
ifconfig.email
ifconfig.es
ifconfig.fi
ifconfig.ga
ifconfig.host
ifconfig.io
ifconfig.is
ifconfig.lt
ifconfig.lv
ifconfig.ms
ifconfig.network
ifconfig.ovh
ifconfig.pm
ifconfig.pro
ifconfig.pw
ifconfig.rs
ifconfig.ru
ifconfig.services
ifconfig.show
ifconfig.software
ifconfig.solutions
ifconfig.systems
ifconfig.technology
ifconfig.top
ifconfig.tw
ifconfig.uk
ifconfig.us
ifconfig.website
ifconfig.xyz

ipconfig.io
ipconfig.org
ipconfig.sh

IP with Carriage Return (\x0D) and Line Feed (\x0A) terminator:
ifconfig.cat

starts with a Horizontal Tab (\x09) character then IP:
ifconfig.ma
ipconfig.ma

IP and other info in JSON format:
ifconfig.wiki


Other domains not curl friendly (try a web browser):
ifconfig.app
ifconfig.at
ifconfig.cloud
ifconfig.com
ifconfig.dk
ifconfig.info
ifconfig.nu
ifconfig.pl
ifconfig.rocks
ipconfig.cz
ipconfig.gq
ipconfig.ie
ipconfig.in
ipconfig.ir
ipconfig.link
ipconfig.no
ipconfig.one
ipconfig.ro
ipconfig.tools
ipconfig.top
ipconfig.us

Other domains curl friendly with path
ifconfig.mx/api
ifconfig.sexy/ip