All these commands check external IP in Linux Terminal for any Linux system.

Commands

Nice format for External IP

curl -s checkip.dyndns.org | sed -e 's/.*Current IP Address: //' -e 's/<.*$//'

Short and Simple to remember

curl ifconfig.co

For those with security concerns without using curl

dig TXT +short o-o.myaddr.l.google.com @ns1.google.com | awk -F'"' '{ print $2}'

Any of these commands will achieve the same result, so pick which one you like best. Personally, for business and professional environments I stick with dig and just make an alias for it, however, for home projects a simple curl ifconfig.co is great.