How to enable tty on nixos

How to enable try (1-6) on nixos , for me only tty7 is working it’s the GUI xorg,
On the bootup time systemd have shown me tty1 is running I don’t know actually what’s happening, but I want to access other tty , if I try to change tty my screen just get freez if I back it tty7 it working again Normal.

The ttys should be available. I can switch to tty4 using Ctrl+Alt+F4
Can you share your config?