How to remotely execute a command or script via telnet?

Question

ubuntu

Hello
Please advise.
There is Ubuntu Server 14.04, from it you need to use a completely open telnet connection without a login and password to remotely execute a command and get the result of the command.
The OS to which we remotely connect via telnet and execute the command is BusyBox.
Command - nc 216.146.43.71 80 | grep -E -o "([0-9]{1,3}[\.]){3}[0-9]{1,3}" works on BusyBox and returns the external IP through which BusyBox exits to the Internet.
It is necessary that this command be executed directly or through a script on Ubuntu and also return the result.
Now the command is being executed, but the result is not returned to the Ubuntu command line, although I tried to add 2>&1 at the end of the line to redirect the output on the advice from the network.
Thanks in advance for your answers!

Answer 1

https://askubuntu.com/questions/1085781/echo-outpu... Is
it?
And in general:
https://www.google.com/search?q=Ubuntu+execute+com...