How to run the game in a separate xorg session, while turning off the main monitor (laptop), and display the game only on the second connected monitor?

Question

X.Org

I managed to run the command xinit game.sh -- :1, but the laptop monitor remains active and the second monitor uses its wrong resolution, and it turns out that I see only a cropped part of the game.
I also want to run the second monitor in 2k resolution, as well. 4k only works at 30 hertz.
I also tried to override the xorg.conf config by setting the -xf86config xorg.conf option - but then the Xs generally fall, swearing that the sneakers cannot start. Most likely because the startkde function is called in the home directory in the .xinitrc config.
How to dance with it at all?

- Manjaro
monitors: eDP1 - laptop, DP-1 - external monitor
xrandr -q
Screen 0: minimum 8 x 8, current 2560 x 1440, maximum 32767 x 32767
eDP1 connected (normal left inverted right x axis y axis)
2160x1440 60.00 +
1792x1344 60.01
2048x1152 59.90 59.91
1920x1200 59.88 59.95
1920x1080 59.96 59.93
1600x1200 60.00
1680x1050 59.95 59.88
1400x1050 59.98
1600x900 59.95 59.82
1280x1024 60.02
1400x900 59.96 59.88
1280x960 60.00
1368x768 59.88 59.85
1280x800 59.81 59.91
1280x720 59.86 59.74
1024x768 60.00
1080x720 60.00
1024x576 59.90 59.82
960x540 59.63 59.82
800x600 60.32 56.25
864x486 59.92 59.57
640x480 59.94
720x405 59.51 58.99
640x360 59.84 59.32
DP1 connected primary 2560x1440 + 0 + 0 (normal left inverted right x axis y axis) 620mm x 340mm
3840x2160 30.00 30.00 25.00 24.00 29.97 23.98
2560x1600 59.97
2560x1440 59.95 *
1920x1080 60.00 60.00 50.00 59.94
1920x1080i 60.00 50.00 59.94
1152x864 75.00
1280x720 60.00 50.00 59.94
1440x576 50.00
1024x768 75.03 70.07 60.00
1440x480 60.00 59.94
832x624 74.55
800x600 72.19 75.00 60.32 56.25
720x576 50.00
720x480 60.00 59.94
640x480 75.00 72.81 66.67 60.00 59.94
720x400 70.08
640x350 70.07
HDMI1 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)