ModuleNotFoundError: No module named 'airflow.providers.slack'

Hello All,

I am using Airflow 2.2 on MWAA Attached is my requirements.txt. I am using slack to send a notification but I am getting an error as "ModuleNotFoundError: No module named 'airflow.providers.slack' ". I have already installed this module saw its installation through Cloudwatch logs also. However, Airflow is not detecting this module. Kindly help me out.

Requirements.txt :

alembic==1.7.7
anyio==3.5.0
apache-airflow-backport-providers-amazon==2021.3.3
apache-airflow-providers-amazon==3.2.0
apache-airflow-providers-ftp==2.1.2
apache-airflow-providers-http==2.1.2
apache-airflow-providers-imap==2.2.3
apache-airflow-providers-slack==4.2.3
apache-airflow-providers-sqlite==2.1.3
apispec==1.3.3
argcomplete==1.12.3
asn1crypto==1.5.1
attrs==20.3.0
Babel==2.9.1
beautifulsoup4==4.10.0
blinker==1.4
boto3==1.15.18
botocore==1.18.18
cached-property==1.5.2
cachelib==0.6.0
cattrs==1.10.0
certifi==2021.10.8
cffi==1.15.0
chardet==3.0.4
charset-normalizer==2.0.12
click==7.1.2
clickclick==20.10.2
colorama==0.4.4
colorlog==4.0.2
commonmark==0.9.1
configparser==3.5.3
connexion==2.13.0
croniter==0.3.37
cryptography==36.0.2
decorator==5.1.1
defusedxml==0.7.1
Deprecated==1.2.13
dill==0.3.4
dnspython==2.2.1
docutils==0.16
email-validator==1.1.3
Flask==1.1.4
Flask-Admin==1.5.4
Flask-AppBuilder==2.3.4
Flask-Babel==1.0.0
Flask-Caching==1.3.3
Flask-JWT-Extended==3.25.1
Flask-Login==0.4.1
Flask-OpenID==1.3.0
Flask-Session==0.4.0
Flask-SQLAlchemy==2.5.1
flask-swagger==0.2.14
Flask-WTF==0.14.3
funcsigs==1.0.2
future==0.18.2
graphviz==0.19.1
gunicorn==20.1.0
h11==0.12.0
httpcore==0.14.7
httpx==0.22.0
idna==2.10
importlib-metadata==4.11.3
importlib-resources==1.5.0
inflection==0.5.1
iso8601==1.0.2
itsdangerous==1.1.0
Jinja2==2.11.3
jmespath==0.10.0
json-merge-patch==0.2
jsonpath-ng==1.5.3
jsonschema==3.2.0
lazy-object-proxy==1.4.3
lockfile==0.12.2
lxml==4.8.0
Mako==1.2.0
Markdown==2.6.11
MarkupSafe==2.0.1
marshmallow==2.21.0
marshmallow-enum==1.5.1
marshmallow-oneofschema==3.0.1
marshmallow-sqlalchemy==0.23.1
mypy-boto3-rds==1.21.34
mypy-boto3-redshift-data==1.21.34
natsort==8.1.0
packaging==21.3
pendulum==1.4.4
ply==3.11
prison==0.2.1
psutil==5.9.0
pycparser==2.21
Pygments==2.11.2
PyJWT==1.7.1
pyparsing==3.0.7
pyrsistent==0.18.1
python-daemon==2.3.0
python-dateutil==2.8.2
python-nvd3==0.15.0
python-slugify==4.0.1
python3-openid==3.2.0
pytz==2021.3
pytzdata==2020.1
PyYAML==6.0
redshift-connector==2.0.905
requests==2.23.0
rfc3986==1.5.0
rich==12.2.0
s3transfer==0.3.7
scramp==1.4.1
setproctitle==1.2.2
six==1.16.0
slack-sdk==3.15.2
slackclient==1.3.2
sniffio==1.2.0
soupsieve==2.3.2
SQLAlchemy==1.3.24
SQLAlchemy-JSONField==0.9.0
sqlalchemy-redshift==0.8.9
SQLAlchemy-Utils==0.38.2
swagger-ui-bundle==0.0.9
tabulate==0.8.9
tenacity==4.12.0
termcolor==1.1.0
text-unidecode==1.3
thrift==0.16.0
typing_extensions==4.1.1
tzlocal==1.5.1
unicodecsv==0.14.1
urllib3==1.25.11
watchtower==0.7.3
websocket-client==0.54.0
Werkzeug==0.16.1
wrapt==1.14.0
WTForms==2.3.3
zipp==3.8.0
zope.deprecation==4.4.0

Thanks. Xi