Cannot find opencv in visual code studio (for c++ in ubuntu)

I am trying to write a code in C++ using Opencv in visual code studio (ubuntu).

I compiled opencv following the next tutorial: http://www.codebind.com/cpp-tutorial/install-opencv-ubuntu-cpp/

And I would like to use Visual code studio, but I am not able to make it work.

My cpp code is the following one:

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <iostream>

// using namespace cv;
// using namespace std;

int main(int argc, char const *argv[])
 {
std::cout << "Hello World\n";

cv::Mat image;
image = cv::imread("image.jpg");   // Read the file
// namedWindow("show image",WINDOW_AUTOSIZE);
//imshow("show image", image);


std::cin.get();
return 0;
}

My c_cpp_propierties.json file is the next one:

{
"configurations": [
    {
        "name": "Linux",
        "browse": {
            "path": [
                "/opt/opencv/include/opencv",
                "${workspaceFolder}"
            ],
            "limitSymbolsToIncludedHeaders": true
        },
        "includePath": [
            "/opt/opencv/include/opencv",
            "${workspaceFolder}/**"
        ],
        "defines": [],
        "compilerPath": "/usr/bin/gcc",
        "cStandard": "c11",
        "cppStandard": "c++17",
        "intelliSenseMode": "clang-x64"
    }
  ],
  "version": 4
}

And the task json is

{
    "version": "2.0.0",
    "tasks": [
    {
        "label": "build hello world",
        "type": "shell",
        "command": "g++",
        "args": [
            "-g", "canny.cpp"
        ],
        "group": {
            "kind": "build",
            "isDefault": true
        }
    }
]
}

When I compile the code I receive the following output:

Executing task: g++ -g canny.cpp <

/tmp/cc01zEdA.o: In function main': /home/beaa/Estudio/CPP/basicOpenCV/canny.cpp:13: undefined reference tocv::imread(cv::String const&, int)' /tmp/cc01zEdA.o: In function cv::String::String(char const*)': /usr/local/include/opencv2/core/cvstd.hpp:597: undefined reference tocv::String::allocate(unsigned long)' /tmp/cc01zEdA.o: In function cv::String::~String()': /usr/local/include/opencv2/core/cvstd.hpp:643: undefined reference tocv::String::deallocate()' /tmp/cc01zEdA.o: In function cv::Mat::~Mat()': /usr/local/include/opencv2/core/mat.inl.hpp:682: undefined reference tocv::fastFree(void*)' /tmp/cc01zEdA.o: In function cv::Mat::release()': /usr/local/include/opencv2/core/mat.inl.hpp:794: undefined reference tocv::Mat::deallocate()' /tmp/cc01zEdA.o: In function cv::Mat::operator=(cv::Mat&&)': /usr/local/include/opencv2/core/mat.inl.hpp:1357: undefined reference tocv::fastFree(void*)' collect2: error: ld returned 1 exit status El proceso del terminal finalizó con el código de salida: 1

As you can see, I use gcc as compiler.

I suppose that the opencv route is not found, but I have tried to fix it and I am not able.

Thanks in advance