Authentication failed in connection to MongoDB Docker container

Question

I deployed MongoDB using docker-compose. In docker-compose.yml I set user authentication

cis_mongodb:
    container_name: cis_mongodb
    image: mongo
    environment:
      MONGO_INITDB_ROOT_USERNAME: ${MONGO_USER}
      MONGO_INITDB_ROOT_PASSWORD: ${MONGO_PASSWORD}

In project root there is a file .env with variables MONGO_USER and MONGO_PASSWORD. I use following code to connect to MongoDB database

import pymongo

dbclient = pymongo.MongoClient(
    f'mongodb://{username}:{password}@{mongo_ip}:{mongo_port}/test',
)

WHen I run this code there is an error

pymongo.errors.OperationFailure: Authentication failed., full error: {'ok': 0.0, 'errsg': 'Authentication failed.', 'code': 18, 'codeName': 'AuthenticationFailed'}

username and password are correct.

I also tried following urls:

f'mongodb://{username}:{password}@{mongo_ip}:{mongo_port}/test'

f'mongodb://{username}:{password}@{mongo_ip}:{mongo_port}/test?authSource=admin'

and this way (tip from here):

import urllib.parse

username = urllib.parse.quote_plus('login')
password = urllib.parse.quote_plus('password')

What can be the cause of the problem?

PS: version of MongoDB is 6.0.8