still no idea why it isn't working

src/main/resources/shaders/shader.frag

@@ -1,5 +1,5 @@
 #version 330 core
-out vec4 FragColor;
+out vec4 fragColor;
 
 
 //uniform float light_power;
@@ -7,7 +7,7 @@ out vec4 FragColor;
 //uniform vec3 objectColor;
 //uniform vec3 viewPos;
 
-in vec3 FragPos;
+// in vec3 FragPos;
 //in vec3 Normal;
 //in vec3 LightPos;
 
@@ -18,6 +18,6 @@ const float screenGamma = 2.2; // Assume the monitor is calibrated to the sRGB c
 
 void main()
 {
-    FragColor = vec4(1.0f, 0.0f, 0.0f, 1.0f);
+    fragColor = vec4(1.0, 0.0, 0.0, 1.0);
 }
 

src/main/resources/shaders/shader.vert

@@ -8,7 +8,7 @@ layout (location = 0) in vec3 aPos;
 uniform mat4 projection;
 // uniform vec3 lightPos;
 
-out vec3 FragPos;
+// out vec3 FragPos;
 // out vec3 Normal;
 // out vec3 LightPos;
 
@@ -16,7 +16,7 @@ void main()
 {
     // * view * model
     gl_Position = projection * model * vec4(aPos, 1.0);
-    FragPos = vec3(vec4(aPos, 1.0));
+//    FragPos = vec3(vec4(aPos, 1.0));
 //     Normal = mat3(transpose(inverse(view * model))) * aNormal;
 //    LightPos = vec3(view * vec4(lightPos, 1.0));
 }