Login failed for the user '' SQL Server when connecting using python from EMR server

Question

I'm trying to connect to SQL Server Database from AWS EMR server.

$cat /etc/odbcinst.ini
[ODBC Driver 17 for SQL Server]
Description=Microsoft ODBC Driver 17 for SQL Server
Driver=/opt/microsoft/msodbcsql17/lib64/libmsodbcsql-17.8.so.1.1
UsageCount=1

and I modified the .odbc.ini file in my home directory like this.

$cat .odbc.ini
[ODBC Data Sources]
studylog = ODBC17Driver

[studylog]
Driver          = /opt/microsoft/msodbcsql17/lib64/libmsodbcsql-17.8.so.1.1
Description     = My Description
Server          = hostname.amazonaws.com

output of odbcinst -j command

unixODBC 2.3.7
DRIVERS............: /etc/odbcinst.ini
SYSTEM DATA SOURCES: /etc/odbc.ini
FILE DATA SOURCES..: /etc/ODBCDataSources
USER DATA SOURCES..: /mnt/efs/home/username/.odbc.ini
SQLULEN Size.......: 8
SQLLEN Size........: 8
SQLSETPOSIROW Size.: 8

output of odbcinst -q -d command

[ODBC Driver 17 for SQL Server]

output of odbcinst -q -s command

[studylog]

Python script I'm using to connect to SQL Server

import pyodbc

host = "hostname.amazonaws.com"
user="DBUser"
password="Password"
db="dbname"

details = {
 'server' : host,
 'database' : db,
 'username' : user,
 'password' : password
 }

# ODBC Driver 17 for SQL Server
connect_string = 'DRIVER={{ODBC Driver 17 for SQL Server}};SERVER={server};PORT={{1433}}; DATABASE={database};UID={username};PWD={password}'.format(**details)
connection = pyodbc.connect(connect_string)
print(connection)

output of my python script

pyodbc.InterfaceError: ('28000', "[28000] [Microsoft][ODBC Driver 17 for SQL Server][SQL Server]Login failed for user 'DBUser'. (18456) (SQLDriverConnect)")

What's going wrong in this? Thank you in advance.