#include not working in webgl 2

[Blechlawine]

the '#include' macro causes a Load error: "Error: Network request failed for url ..." code:

#version 300 es

#include "/_ray.glsl"

precision mediump float;

uniform vec2 u_resolution;
uniform vec2 u_mouse;
uniform float u_time;

out vec4 fragColor;
void main() {
    fragColor = vec4(1., 0., 0.5, 1.);
}

The error message:

I tried a relative path as well and it said syntax error?

[pixelprato]

Have the same