@Hoxbro Hey, thanks for the reply! 
Yes, I followed the instructions to a tee, as you can see the app is deployed Panel Application
but the template just isn’t loading right, you can see the title is loading in one of the broken boxes.
Procfile:
web: panel serve --address="0.0.0.0" --port=$PORT deploy.py --allow-websocket-origin=stopwatch-tracker.herokuapp.com
It had to use some older versions of Panel and Pydeck to get it running without any errors.
Requirements.txt
numpy==1.24.2
pandas==1.5.3
geopandas==0.12.2
pydeck===0.7.1
panel==0.14.1
panel_highcharts
matplotlib
folium
hvplot
js2py
jupyterlab
This is the error I get when running locally and on heroku when using the latest versions of panel and pydeck.
2023-04-28T13:07:54.705260+00:00 app[web.1]: Traceback (most recent call last):
2023-04-28T13:07:54.705269+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.10/site-packages/tornado/web.py", line 1786, in _execute
2023-04-28T13:07:54.705269+00:00 app[web.1]: result = await result
2023-04-28T13:07:54.705271+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.10/site-packages/panel/io/server.py", line 338, in get
2023-04-28T13:07:54.705271+00:00 app[web.1]: session = await self.get_session()
2023-04-28T13:07:54.705272+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.10/site-packages/bokeh/server/views/session_handler.py", line 144, in get_session
2023-04-28T13:07:54.705272+00:00 app[web.1]: session = await self.application_context.create_session_if_needed(session_id, self.request, token)
2023-04-28T13:07:54.705273+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.10/site-packages/bokeh/server/contexts.py", line 243, in create_session_if_needed
2023-04-28T13:07:54.705273+00:00 app[web.1]: self._application.initialize_document(doc)
2023-04-28T13:07:54.705273+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.10/site-packages/panel/io/server.py", line 301, in initialize_document
2023-04-28T13:07:54.705273+00:00 app[web.1]: template.server_doc(title=template.title, location=True, doc=doc)
2023-04-28T13:07:54.705274+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.10/site-packages/panel/template/base.py", line 348, in server_doc
2023-04-28T13:07:54.705274+00:00 app[web.1]: return self._init_doc(doc, title=title, location=location)
2023-04-28T13:07:54.705275+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.10/site-packages/panel/template/base.py", line 575, in _init_doc
2023-04-28T13:07:54.705275+00:00 app[web.1]: document = super()._init_doc(doc, comm, title, notebook, location)
2023-04-28T13:07:54.705275+00:00 app[web.1]: File "/app/.heroku/python/lib/python3.10/site-packages/panel/template/base.py", line 197, in _init_doc
2023-04-28T13:07:54.705275+00:00 app[web.1]: if self._apply_hooks not in obj._hooks:
2023-04-28T13:07:54.705275+00:00 app[web.1]: AttributeError: 'FastGridTemplate' object has no attribute '_hooks'