THINGS TO KEEP IN MIND:

1. Make sure the Camera is centered on the Geometry Nodes object and camera's Orthographic Scale = 2

2. Do not scale or rotate the Seamless Scatter object.

3. If you need to light the scene, use Sun Light.

4. Under Output properties, lower the 'Compression' value to 0%.

5. Change the filter size to 0.01px (This will get rid of the white border on your render, resulting in a perfect seamless image)

EEVEE: ‘Properties’ window > ‘Render Properties’ tab > ‘Film’ change the ‘Filter Size’ value to 0.01px
CYCLES: ‘Properties’ window > ‘Render Properties’ tab > ‘Film’ > ‘Pixel Filter’ change the ‘Width’ value to 0.01px