Heroku ImportError: cannot import name 'secure_filename' from 'werkzeug'

Question

I deployed my Flask app on Heroku but the application crashes due to the import error above. I tried to change this line

from werkzeug import secure_filename, FileStorage

to this

from werkzeug.datastructure import FileStorage
from werkzeug.utils import secure_filename

I also included Flask-Reuploaded package in my requirements.txt file

Flask-Reuploaded==1.2.0

But it still gives me the same error.