Draw a pixel to the screen in x86-64 assembly

I've been trying to draw even 1 pixel to the screen in x86-64 assembly with masm visual studio

I've found online that you can use int 10h to make the screen into 320x200 256 color mode but when i try to use this i get an error

Exception thrown at 0x00007FF6F2341014 in assemblyproject.exe: 0xC0000005: Access violation reading location 0xFFFFFFFFFFFFFFFF.

and i cant make this go away

I've also found that 0xA0000h is the location in memory to draw to the screen but when i try to write there i get another error

Exception thrown at 0x00007FF7A4AF101F in assemblyproject.exe: 0xC0000005: Access violation writing location 0x00000000000A0000.

i have tried for multiple days to make this work but i have not even gotten 1 pixel onto the screen and i don't know what more i can do or how to fix anything

I'm using windows 10 operating system