python - FAB custom add-on create and install

I am trying to build my own custom add-on in order to handle OAuth login external to my application in a generic way.

I have read the documentation on implementing OAuth, as well as the documentation on creating add-ons. I have the code working if I hack it into the application (no add-on), but I don't want this. I want it in such a way that I can simply include the code and set a variable in my config.py to use it. That's why I am trying the add-on thing.

I moved the code I got working inside the application out to the add-on. I used the fabmanager to generate the skeleton for me, then just fixed the model.py file, which is where my code sits, and the config files. Then I added the below line, as per the docs, in my main app's config.py file to tell it to use my add-on.

ADDON_MANAGERS = ['fab_addon_x.manager.X']

This does not work however. I get a "ModuleNotFoundError".

File "/usr/local/lib/python3.6/site-packages/flask_appbuilder/base.py", line 30, in dynamic_class_import
  package = __import__(module_path)
ModuleNotFoundError: No module named 'fab_addon_x'

I've placed the add-on code both on the same level as the main project:

/myapp/
/fab_addon_x/

and inside the main project:

/myapp/
/myapp/fab_addon_x/

Neither of these work.

Full folder structure

/usr/local/lib/python3.6/site-packages/myapp/
  - __init__.py
  - __pycache__
  - bin
  - cache_util.py
  - cli.py
  - config.py
  - connectors
  - data
  - dataframe.py
  - db_engine_specs.py
  - db_engines
  - dict_import_export_util.py
  - extract_table_names.py
  - forms.py
  - import_util.py
  - jinja_context.py
  - legacy.py
  - migrations
  - models
  - security.py
  - sql_lab.py
  - sql_parse.py
  - static
  - stats_logger.py
  - templates
  - translations
  - utils.py
  - views
  - viz.py

I've placed the add-on folder both at this level and one level up. Add-on folder structure:

fab_addon_x
  - README.rst
  - config.py
  - fab_addon_x
      - __init__.py
      - manager.py
      - models.py
      - templates
      - translations
      - version.py
      - views.py
  - run.py
  - setup.py

Is there a specific way to register my add-on? Or is this a straight forward referencing issue that I just can't seem to figure out?

Edit 1

Changed "ADDON_MANAGERS = ['fab_addon_first.manager.FirstAddOnManager']" to what it is now.

Edit 2

Added folder structure

Solution

So I figured out my own issue here. The docs doesn't mention this anywhere, but if you don't upload your add-on to the registry and just copy the files into the directory you first have to install it. This probably sounds self-explanatory for those familiar with python, but I'm not, so it wasn't for me.

The below command will install it and you should be good to go:

python setup.py install