can't do this ./build.py --toolchain aarch64-linux-android or found it to build that for a kivy project

[Evil4eveR]

first, i m using ubuntu from my windows and I have a problem converting my kivy code to apk and i search for solutions and nothing worked and i tied this solution https://github.com/mzakharo/android-gfortran
after I did that command
repo init -u https://android.googlesource.com/platform/manifest -b gcc
I couldn't find build.py as it said in the link In toolchain/gcc/build-gcc.sh, find the line that contains:

anyhelp please

the error i had is

[WARNING]: install_libs called with no libraries to install!
[INFO]:    Building lapack for armeabi-v7a
[INFO]:    -> directory context /mnt/c/users/ymarmoud/Desktop/RecoVineApp/.buildozer/android/platform/build-arm64-v8a_armeabi-v7a/build/other_builds/lapack/armeabi-v7a__ndk_target_21/lapack/build
[ERROR]:   Build failed: /home/hisoka/.buildozer/android/platform/android-ndk-r21e/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin/arm-linux-androideabi-gfortran not found. See https://github.com/mzakharo/android-gfortran
# Command failed: ['/usr/bin/python3', '-m', 'pythonforandroid.toolchain', 'create', '--dist_name=RecoVine', '--bootstrap=sdl2', '--requirements=python3,kivy==2.0.0,kivymd==0.104.2,threading,webbrowser,datetime,pillow,plyer,cv2,opencv,imutils,numpy,collections,keras,scipy', '--arch=arm64-v8a', '--arch=armeabi-v7a', '--copy-libs', '--color=always', '--storage-dir=/mnt/c/users/ymarmoud/Desktop/RecoVineApp/.buildozer/android/platform/build-arm64-v8a_armeabi-v7a', '--ndk-api=21', '--ignore-setup-py', '--debug']