Hi MinhChau96,
I deployed my app following the docs guide https://dash.plotly.com/deployment then I replaced the example app for my app and had no errors.
The difference I can see between the example and your files is that you are including a runtime.txt file that is not speciffy in the docs and also in the requirements.txt there is no loading Flask:
Flask==1.1.2
Flask-Compress==1.7.0
I have no technical knowledge about deploying heroku app and I can’t tell if any of those observation means something.