Attempting to force my game to render at a specific resolution

I have a question about the Render Pipeline, and specifically if it was possible to lower the game resolution to a specific resolution for a stylistic reason. The reason is simply that I want to achieve this look without using a shader that reduces the quality:

The Shader takes the pixels render on screen and creates the pixelated look. It does a good job at this however it of course runs into the usual issue that since it is diminishing the quality it would probably preform significantly better if it just, renders out at the resolution first than up scaling. IDK how much this would change, probably a lot, but the only thing I could find about this is however it appears to not work: How can i render game (3d) at lower resolution and then upsample it to look like 8bit pixelart game?

Any advice?