Setup error in Debian 10 aarch64

[yd2005]

Installed /usr/local/lib/python3.7/dist-packages/Flask_Login-0.4.1-py3.7.egg
Searching for bcrypt==3.2.0
Reading https://pypi.org/simple/bcrypt/
Downloading https://files.pythonhosted.org/packages/d8/ba/21c475ead997ee21502d30f76fd93ad8d5858d19a3fad7cd153de698c4dd/bcrypt-3.2.0.tar.gz#sha256=5b93c1726e50a93a033c36e5ca7fdcd29a5c7395af50a6892f5d9e7c6cfbfb29
Best match: bcrypt 3.2.0
Processing bcrypt-3.2.0.tar.gz
Writing /tmp/easy_install-p91cszr2/bcrypt-3.2.0/setup.cfg
Running bcrypt-3.2.0/setup.py -q bdist_egg --dist-dir /tmp/easy_install-p91cszr2/bcrypt-3.2.0/egg-dist-tmp-2mv3x6rx
c/_cffi_backend.c:15:10: fatal error: ffi.h: No such file or directory
#include <ffi.h>
^~~~~~~
compilation terminated.
error: Setup script exited with error: command 'aarch64-linux-gnu-gcc' failed with exit status 1

[emwadde]

Can u try re-installing build-essential