Unable to open display - error

I ran the command below on [secureCRT](https://www.vandyke.com/download/securecrt/download.html) ssh client: $ DISPLAY=abc.xyz.com:0 ; export DISPLAY $ /bin/xhost +abc.xyz.com But it output this error: /bin/xhost: unable to open display "abc.xyz.com" # cat /etc/system-release Red Hat Enterprise Linux Server release 7.5 (Maipo) # whoami root How to troubleshoot this error?