how to wget a file on a remote server connected using ssh?

I am connected to my university computer using SSH as follows :

sudo ssh server@A.B.C.D

However once connected, I'm not able to download any file on the server using wget like this :

server_user@server:~$ wget http://example.com/somefile 

If I do that, I get following error:

--2020-07-28 10:14:46--  https://example.com/somefile 
Resolving example.com (example.com)... failed: Name or service not known.
wget: unable to resolve host address ‘example.com’

Also I'm not able to install any package using pip on the remote server. How shoud I do these things? Thanks in advance :) PS : of course the address is not the example.com. I've just used it temporarily here for the example purpose. It is a real http address from which I can download file locally using wget, but doing it on server raises the error reported above.