Getting an error from AWS when trying to apply deployment with S3 storage block.

from flows.helloworld.helloworld_flow import helloworld
from prefect.deployments import Deployment
from prefect_aws.ecs import ECSTask
from prefect_aws.s3 import S3Bucket

s3_storage = S3Bucket.load("prod")

ecs_task = ECSTask.load("prod")

helloworld_deployment = Deployment.build_from_flow(
    flow=helloworld,
    name="Hello World",
    storage=s3_storage,
    path="helloworld",
    infrastructure=ecs_task,
)

helloworld_deployment.apply()

is giving me

$ python deployments.py 
Traceback (most recent call last):
  File "~/.pyenv/versions/prefect/lib/python3.10/site-packages/s3fs/core.py", line 112, in _error_wrapper
    return await func(*args, **kwargs)
  File "~/.pyenv/versions/prefect/lib/python3.10/site-packages/aiobotocore/client.py", line 358, in _make_api_call
    raise error_class(parsed_response, operation_name)
botocore.exceptions.ClientError: An error occurred (SignatureDoesNotMatch) when calling the PutObject operation: The request signature we calculated does not match the signature you provided. Check your key and signing method.

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "~/code/wfp/wfp-prefect/deployments.py", line 29, in <module>
    helloworld_deployment = WFPDeployment(
  File "~/.pyenv/versions/prefect/lib/python3.10/site-packages/prefect/utilities/asyncutils.py", line 230, in coroutine_wrapper
    return run_async_in_new_loop(async_fn, *args, **kwargs)
  File "~/.pyenv/versions/prefect/lib/python3.10/site-packages/prefect/utilities/asyncutils.py", line 181, in run_async_in_new_loop
    return anyio.run(partial(__fn, *args, **kwargs))
  File "~/.pyenv/versions/prefect/lib/python3.10/site-packages/anyio/_core/_eventloop.py", line 70, in run
    return asynclib.run(func, *args, **backend_options)
  File "~/.pyenv/versions/prefect/lib/python3.10/site-packages/anyio/_backends/_asyncio.py", line 292, in run
    return native_run(wrapper(), debug=debug)
  File "~/.pyenv/versions/3.10.9/lib/python3.10/asyncio/runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "~/.pyenv/versions/3.10.9/lib/python3.10/asyncio/base_events.py", line 649, in run_until_complete
    return future.result()
  File "~/.pyenv/versions/prefect/lib/python3.10/site-packages/anyio/_backends/_asyncio.py", line 287, in wrapper
    return await func(*args)
  File "~/.pyenv/versions/prefect/lib/python3.10/site-packages/prefect/deployments.py", line 755, in build_from_flow
    await deployment.upload_to_storage(ignore_file=ignore_file)
  File "~/.pyenv/versions/prefect/lib/python3.10/site-packages/prefect/deployments.py", line 600, in upload_to_storage
    file_count = await self.storage.put_directory(
  File "~/.pyenv/versions/prefect/lib/python3.10/site-packages/prefect/filesystems.py", line 492, in put_directory
    return await self.filesystem.put_directory(
  File "~/.pyenv/versions/prefect/lib/python3.10/site-packages/prefect/filesystems.py", line 368, in put_directory
    self.filesystem.put_file(f, fpath, overwrite=True)
  File "~/.pyenv/versions/prefect/lib/python3.10/site-packages/fsspec/asyn.py", line 114, in wrapper
    return sync(self.loop, func, *args, **kwargs)
  File "~/.pyenv/versions/prefect/lib/python3.10/site-packages/fsspec/asyn.py", line 99, in sync
    raise return_result
  File "~/.pyenv/versions/prefect/lib/python3.10/site-packages/fsspec/asyn.py", line 54, in _runner
    result[0] = await coro
  File "~/.pyenv/versions/prefect/lib/python3.10/site-packages/s3fs/core.py", line 1101, in _put_file
    await self._call_s3(
  File "~/.pyenv/versions/prefect/lib/python3.10/site-packages/s3fs/core.py", line 339, in _call_s3
    return await _error_wrapper(
  File "~/.pyenv/versions/prefect/lib/python3.10/site-packages/s3fs/core.py", line 139, in _error_wrapper
    raise err
PermissionError: The request signature we calculated does not match the signature you provided. Check your key and signing method.

Usually when I've run into this with S3, it's been because I accidentally copied and pasted a space before or after my key or secret - or accidentally cut off a character. Either way, re-entering and double-checking your credentials is a good first step just to get the simplest thing out of the way first.