Git Bash can't find cmake

I followed the instruction in the link: OpenCV: Installation in Windows
And the command below doesn’t work as expected at line 27.
Cmake doesn’t find. I did setup the system environment variable. It works in windows console command line, but doesn’t work in gitbash.
How can I fix it?

#!/bin/bash -e
myRepo=$(pwd)
CMAKE_GENERATOR_OPTIONS=-G"Visual Studio 16 2019"
#CMAKE_GENERATOR_OPTIONS=-G"Visual Studio 15 2017 Win64"
#CMAKE_GENERATOR_OPTIONS=(-G"Visual Studio 16 2019" -A x64)  # CMake 3.14+ is required
if [  ! -d "$myRepo/opencv"  ]; then
    echo "cloning opencv"
    git clone https://github.com/opencv/opencv.git
else
    cd opencv
    git pull --rebase
    cd ..
fi
if [  ! -d "$myRepo/opencv_contrib"  ]; then
    echo "cloning opencv_contrib"
    git clone https://github.com/opencv/opencv_contrib.git
else
    cd opencv_contrib
    git pull --rebase
    cd ..
fi
RepoSource=opencv
mkdir -p build_opencv
pushd build_opencv
CMAKE_OPTIONS=(-DBUILD_PERF_TESTS:BOOL=OFF -DBUILD_TESTS:BOOL=OFF -DBUILD_DOCS:BOOL=OFF  -DWITH_CUDA:BOOL=OFF -DBUILD_EXAMPLES:BOOL=OFF -DINSTALL_CREATE_DISTRIB=ON)
set -x
**cmake "${CMAKE_GENERATOR_OPTIONS[@]}" "${CMAKE_OPTIONS[@]}" -DOPENCV_EXTRA_MODULES_PATH="$myRepo"/opencv_contrib/modules -DCMAKE_INSTALL_PREFIX="$myRepo/install/$RepoSource"** "$myRepo/$RepoSource"
echo "************************* $Source_DIR -->debug"
cmake --build .  --config debug
echo "************************* $Source_DIR -->release"
cmake --build .  --config release
cmake --build .  --target install --config release
cmake --build .  --target install --config debug
popd

Apparently you have to install cmake and add its location to the PATH environment variable and check if has propagated to git-bash: echo $PATH.