I try to get the logs one minute before the crash occurs. But I find it complicated what actually causes this problem.

Maybe it's the Nvidia drivers 570.86.15 or not.

Ctrl + Alt + Fx doesn't response, just I receive a "sad face" from Ubuntu.

Your system information

• Steam client version (build number or date): 1745457196
• Distribution (e.g. Ubuntu): Ubuntu 24.04
• Opted into Steam client beta?: Yes
• Have you checked for system updates?: Yes
• Steam Logs: [generate by running this command in a terminal tar -zcvf ~/Desktop/steam-logs.tar.gz ~/.steam/steam/logs]
• GPU: Nvidia/Intel/AMD Nvidia drivers 570.86.15

Please describe your issue in as much detail as possible:

Just open Steam

Edit:
with this commands:

journalctl -p 3 --since "1 min ago"
grep -i "error\|nvidia" /var/log/kern.log | tail -n 20
cat ~/.local/share/xorg/Xorg.1.log

I get this all information:

diagnostics.txt