NCview: my Macbook "can't open display"

I have installed NCview after downloading MacPorts today. But it does not work with "Error: Can't open display".

I have looked several discussions but none was with Monterey.

I tried below for Big Sur but did not work.

grep DISPLAY ~/.*rc ~/.login ~/.*profile ~/.MacOSX/environment.plist 2>/dev/null

/Users/XXXX/.zprofile:#export DISPLAY=:0

It would be appreciated if anyone give my any help.

Thank you!