How do I turn off Nvidia sync?

I have an LG ultragaming oled monitor, I know how to turn the settings of but every time I try to keep it off my pc just refuses to work, one time I turned off the vsync in my monitor while the pc was turned off and the pc kept boot looping until I turn it back on.

I want to turn it off because the oled monitor have this… how do I describe it? The display keeps blinking at random, like it’s trying to adjust the lighting every time but never settling down, usually I just endure it but this time after a session with my friends I have my eyes hurting like hell.