Adjusting Screen Resolution on TeamViewer Without Connected Monitor

Hello,
I haven't found an answer to my problem anywhere, so let me ask.

I use one of the computers as a server but only connect to it once in a while via Team Viewer. No monitor is connected to the graphics card.
After Team Viewer is connected, the screen works in 800x600 resolution.
I want to change the resolution to a more affordable one, but since no screen is detected, I can't change the resolution.
Anyone know how to do this?
I will be grateful for your help.

Do you use Team Viewer or VNC? Was it not visible outside?

Team Viewer.
After connecting the monitor to the hdmi, the card changes the resolution to the one I want, and after disconnecting the moitor, it returns to low resolution.

In TeamViewer advanced options I found monitor driver installations, installed and I don't know what to do next. After turning off the monitor, the resolution changes, maybe someone knows what to do next to set your own resolution without the monitor.

https://community.teamviewer.com/t5/Knowledge...-use-TeamViewer-on-headless-systems/ta-p/4256

Quote:

Please make sure to connect a graphics display to the device. It may also be sufficient to connect a dummy plug to your graphics card.

Maybe connect the cable itself to the graphics card without connecting any monitor?

With this monitor driver, I don't know - I haven't tested what it gives.