Use MKL for BLAS CMake in C++ application

I would like to use MKL for BLAS operations. What should I set in my CMakeLists please? Do I need to enable any other build flags and or macros? Below see what my project CMakeLists looks like.

find_package(Torch REQUIRED PATHS /usr/local/libtorch)

Calling C++ code looks like this:

#include <benchmark/benchmark.h>

#include <torch/torch.h>

static void torch_tensor_mult_test(benchmark::State &state) {
  int size = state.range(0);
  torch::Tensor m = torch::rand({size, size});
  torch::Tensor v = torch::rand({size, 1});
  torch::Tensor r = torch::rand({size, 1});

  for (auto _ : state) {
    r = m * v;
BENCHMARK(torch_tensor_mult_test)->RangeMultiplier(2)->Range(2, 8 << 7);