在heroku中部署后，“未找到模块：tkinter”

Question

ModuleNotFoundError at /
No module named '_tkinter'
Request Method: GET
Request URL:    https://facerecogs.herokuapp.com/
Django Version: 2.2.6
Exception Type: ModuleNotFoundError
Exception Value:    
No module named '_tkinter'
Exception Location: /app/.heroku/python/lib/python3.6/tkinter/__init__.py in <module>, line 36
Python Executable:  /app/.heroku/python/bin/python
Python Version: 3.6.10
Python Path:    
['/app/.heroku/python/bin',
 '/app',
 '/app/.heroku/python/lib/python36.zip',
 '/app/.heroku/python/lib/python3.6',
 '/app/.heroku/python/lib/python3.6/lib-dynload',
 '/app/.heroku/python/lib/python3.6/site-packages']
Server time:    Wed, 22 Jan 2020 09:32:02 +0000