Heroku Deploy: dash.exceptions.NoLayoutException
This is what worked for me:
index.py
from app import app, serverapp.py
server = app.serverProcfile
web: gunicorn index:serverApparently, that multi-app example you linked to, the one in the offical Dash docs, has a mistake. Gunicorn doesn't accept the syntax, <file>:<variable>.<sub-variable>. This forum thread pointed me towards this solution: