Ubuntu 20.04.6 external display doesn't work on my new laptop

I got a new XPS 15 9530 with following specs;

• i9 13th gen
• RTX 4070
• 3.5k OLED Display

I turned off secure boot and install Ubuntu 20.04.6 and I keep facing some problems. I think I have a driver problem. I try following solutions but none of them works:

1. I select NVIDIA 525 all options from additional drivers but none of them works
2. I try x.org driver but it doesn't work too
3. I download 530 from NVIDIA website and install but doesn't work
4. I update grub with quiet splash to quiet splash nomodeset but doesn't work
5. I try perfomance mode over nvidia-prime but it gives black screen on startup. I redo from recovery mode
6. I update kernel to 5.15.0-69-generic but nothing changed
7. I did purge and autoremove for NVIDIA but nothing changed again

When I go to Display on settings, my screen shown like 'Unknown Display' with 3456x2160 resolution. I also want to use with 1080 but there is no option like this. I try to add resolution from terminal with following code:

sudo xrandr --newmode "2560x1080_60.00" 272.25 2560 2736 3008 3456 1080 1083 1093 1127 -hsync +vsync

But I got following error:

xrandr: Failed to get size of gamma for output default

I am trying to connect to external monitor with a type-c to hdmi converter. I try with several converter but none of them works. I feel like all about drivers but I couldn't figure out how to use external display. I am not professional on Ubuntu. Can you please guide me towards and appropriate solution?

EDIT:

My laptop's motherboard model number: