poetry unable to load sqlalchemy stubs

pyproject.toml

[tool.poetry]
name = "flask-sqlalchemy"
version = "0.0.1"
description = ""
authors = ["kracekumar <>"]
license = "MIT"
readme = ""
repository = ""

[tool.poetry.dependencies]
python = "^3.6.1"
alabaster = "^0.7.12"
appdirs = "^1.4.4"
attrs = "^21.2.0"
Babel = "^2.9.1"
blinker = "^1.4"
certifi = "^2021.5.30"
cfgv = "^3.3.0"
chardet = "^4.0.0"
click = "^8.0.1"
distlib = "^0.3.2"
docutils = "^0.17.1"
filelock = "^3.0.12"
identify = "^2.2.10"
idna = "^3.2"
imagesize = "^1.2.0"
iniconfig = "^1.1.1"
Jinja2 = "^3.0.1"
MarkupSafe = "^2.0.1"
mock = "^4.0.3"
nodeenv = "^1.6.0"
packaging = "^20.9"
Pallets-Sphinx-Themes = "^2.0.1"
pep517 = "^0.10.0"
pip-tools = "^6.1.0"
pluggy = "^0.13.1"
pre-commit = "^2.13.0"
py = "^1.10.0"
Pygments = "^2.9.0"
pyparsing = "^2.4.7"
pytest = "^6.2.4"
pytz = "^2021.1"
PyYAML = "^5.4.1"
six = "^1.16.0"
snowballstemmer = "^2.1.0"
sphinx-issues = "^1.2.0"
Sphinx = "^4.0.2"
sphinxcontrib-applehelp = "^1.0.2"
sphinxcontrib-devhelp = "^1.0.2"
sphinxcontrib-htmlhelp = "^2.0.0"
sphinxcontrib-jsmath = "^1.0.1"
sphinxcontrib-log-cabinet = "^1.0.1"
sphinxcontrib-qthelp = "^1.0.3"
sphinxcontrib-serializinghtml = "^1.1.5"
toml = "^0.10.2"
tox = "^3.23.1"
urllib3 = "^1.26.5"
virtualenv = "^20.4.7"
SQLAlchemy = {extras = ["mypy"], version = "^1.4.18"}

[build-system]
requires = ["poetry-core>=1.0.0"]
build-backend = "poetry.core.masonry.api"