Cannot run FastAPI Docker image : Docker ModuleNotFoundError - docker

Question

This is my application structure:
project/
├── Dockerfile
├── example_api
│   └── main.py
└── requirements.txt
Here is the Dockerfile
FROM python:3.9-slim
COPY ./example_api /app/src
COPY ./requirements.txt /app
WORKDIR /app
RUN pip3 install -r requirements.txt
EXPOSE 8000
CMD ["uvicorn", "example_api.main:app", "--host=0.0.0.0", "--reload"]
building with
docker build -t siddesh-fastapi:0.1 .
running with
docker run -p 8000:8000 --name siddesh-test-api siddesh-fastapi:0.1
error message
INFO: Will watch for changes in these directories: ['/app']
INFO: Uvicorn running on http://0.0.0.0:8000 (Press CTRL+C to quit)
INFO: Started reloader process [1] using watchgod
Process SpawnProcess-1:
Traceback (most recent call last):
File "/usr/local/lib/python3.9/multiprocessing/process.py", line 315, in _bootstrap
self.run()
File "/usr/local/lib/python3.9/multiprocessing/process.py", line 108, in run
self._target(*self._args, **self._kwargs)
File "/usr/local/lib/python3.9/site-packages/uvicorn/subprocess.py", line 76, in subprocess_started
target(sockets=sockets)
File "/usr/local/lib/python3.9/site-packages/uvicorn/server.py", line 68, in run
return asyncio.run(self.serve(sockets=sockets))
File "/usr/local/lib/python3.9/asyncio/runners.py", line 44, in run
return loop.run_until_complete(main)
File "uvloop/loop.pyx", line 1501, in uvloop.loop.Loop.run_until_complete
File "/usr/local/lib/python3.9/site-packages/uvicorn/server.py", line 76, in serve
config.load()
File "/usr/local/lib/python3.9/site-packages/uvicorn/config.py", line 448, in load
self.loaded_app = import_from_string(self.app)
File "/usr/local/lib/python3.9/site-packages/uvicorn/importer.py", line 24, in import_from_string
raise exc from None
File "/usr/local/lib/python3.9/site-packages/uvicorn/importer.py", line 21, in import_from_string
module = importlib.import_module(module_str)
File "/usr/local/lib/python3.9/importlib/__init__.py", line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
File "<frozen importlib._bootstrap>", line 972, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 228, in _call_with_frames_removed
File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
File "<frozen importlib._bootstrap>", line 984, in _find_and_load_unlocked
ModuleNotFoundError: No module named 'example_api'
I guess I am missing something in the Dockerfile?