Creating material with math calculations, no vector available, no texture data info

I need to implement this code:

vec4 texturePointSmooth(sampler2D tex, vec2 uv) {
	vec2 size = vec2(textureSize(tex, 0));
	vec2 pixel = vec2(1.0) / size;
	uv -= pixel * vec2(0.5);
	vec2 uv_pixels = uv * size;
	vec2 delta_pixel = fract(uv_pixels) - vec2(0.5);
	vec2 ddxy = fwidth(uv_pixels);
	vec2 mip = log2(ddxy) - 0.5;
	return textureLod(tex, uv + (clamp(delta_pixel / ddxy, 0.0, 1.0) - delta_pixel) * pixel, min(mip.x, mip.y));
}

In unreal engine5 for texture/shaders/etc. I’m using “Material” from duplicate of papersprite2d
I’m trying to get size of input texture - no node available
I’m trying to hardcode values of size - no node to make vector available. Am i looking on a right place?

image

Texture Property and Constant2Vector respectively
You can hold 1,2,3,4 on your keyboard and click and it will add a scalar, vec2, vec3, vec4 node in the graph