curl checkip.amazonaws.com
curl ipv4.icanhazip.com
curl ifconfig.me -w "\n"
(There are others.)
(There are others that do the same.)
https://www.ipaddressguide.com/ipv6-cidr
https://toolbox.googleapps.com/apps/dig/
See: https://dev.maxmind.com/geoip/geolite2-free-geolocation-data/