Xlib.error.DisplayConnectionError: Can't connect to display ":0": b'No protocol specified\n' about xkeysnail HOT 3 CLOSED

kozo2@kozo2-XPS-13-9343:~/Downloads/xkeysnail-master/example$ xhost +
access control disabled, clients can connect from any host
kozo2@kozo2-XPS-13-9343:~/Downloads/xkeysnail-master/example$ sudo xhost +
[sudo] password for kozo2: 
access control disabled, clients can connect from any host
kozo2@kozo2-XPS-13-9343:~/Downloads/xkeysnail-master/example$ sudo xkeysnail config.py 

██╗  ██╗██╗  ██╗███████╗██╗   ██╗
╚██╗██╔╝██║ ██╔╝██╔════╝╚██╗ ██╔╝
 ╚███╔╝ █████╔╝ █████╗   ╚████╔╝
 ██╔██╗ ██╔═██╗ ██╔══╝    ╚██╔╝
██╔╝ ██╗██║  ██╗███████╗   ██║
╚═╝  ╚═╝╚═╝  ╚═╝╚══════╝   ╚═╝
  ███████╗███╗   ██╗ █████╗ ██╗██╗
  ██╔════╝████╗  ██║██╔══██╗██║██║
  ███████╗██╔██╗ ██║███████║██║██║
  ╚════██║██║╚██╗██║██╔══██║██║██║
  ███████║██║ ╚████║██║  ██║██║███████╗
  ╚══════╝╚═╝  ╚═══╝╚═╝  ╚═╝╚═╝╚══════╝
                             v0.1.0

No keyboard devices specified via (--devices) option.
xkeysnail picks up keyboard-ish devices from the list below:

----------------------------------------------------------------------------------
Device               Name                                Phys
----------------------------------------------------------------------------------
/dev/input/event0    Lid Switch                          PNP0C0D/button/input0
/dev/input/event1    Power Button                        PNP0C0C/button/input0
/dev/input/event2    Sleep Button                        PNP0C0E/button/input0
/dev/input/event3    Power Button                        LNXPWRBN/button/input0
/dev/input/event4    AT Translated Set 2 keyboard        isa0060/serio0/input0
/dev/input/event5    Video Bus                           LNXVIDEO/video/input0
/dev/input/event6    Integrated_Webcam_HD: Integrate     usb-0000:00:14.0-5/button
/dev/input/event7    Dell WMI hotkeys                    
/dev/input/event8    DLL0665:01 06CB:76AD Touchpad       i2c-DLL0665:01
/dev/input/event9    HDA Intel PCH Headphone Mic         ALSA
/dev/input/event10   HDA Intel HDMI HDMI/DP,pcm=3        ALSA
/dev/input/event11   HDA Intel HDMI HDMI/DP,pcm=7        ALSA
/dev/input/event12   HDA Intel HDMI HDMI/DP,pcm=8        ALSA
/dev/input/event13   HDA Intel HDMI HDMI/DP,pcm=9        ALSA
/dev/input/event14   HDA Intel HDMI HDMI/DP,pcm=10       ALSA
/dev/input/event15   py-evdev-uinput                     py-evdev-uinput

Okay, now enable remapping on the following device(s):

------------------------------------------------------------------------------
Device               Name                                Phys
------------------------------------------------------------------------------
/dev/input/event4    AT Translated Set 2 keyboard        isa0060/serio0/input0

WM_CLASS 'Gnome-terminal' | active keymaps = []
C-Shift-C