SQL IM002 Errors while connecting to SQL Server from perl on heroku

I have a perl application hosted on heroku which needs to connect with some sql server. I am unable to establish connection. It fails with following error:

DBI connect('Driver={ODBC Driver 11 For SQL Server}; Server=****; UID=****; PWD=****','',...) failed: [unixODBC][Driver Manager]Data source name not found, and no default driver specified (SQL-IM002) at work.pl line 12.

This is the code.

work.pl

use strict;
use warnings;

use DBI;


my $DRIVER = '{ODBC Driver 11 for SQL Server}';
my $SERVER = '****';
my $UID = '****';
my $PWD = '****';

my $x = DBI->connect("dbi:ODBC:Driver=$DRIVER; Server=$SERVER; UID=$UID; PWD=$PWD");

Relevant Environment Vars:

LIBRARY_PATH=/app/.platform/vendor/usr/lib64:
LD_LIBRARY_PATH=/app/.platform/vendor/usr/lib64:
PATH=/app/.platform/vendor/usr/bin:/app/vendor/perl/bin:/usr/bin:/bin
LANG=en_US.UTF-8
ODBCSYSINI=/app/.platform/vendor/etc
HOME=/app
PWD=/app
ODBCINI=/app/.platform/vendor/etc/odbc.ini
ODBCHOME=/app/.platform/vendor/etc/
PERL5OPT=-Mlocal::lib=/app/vendor/perl-deps

odbcinst.ini:

Description             = ODBC for PostgreSQL
Driver          = /usr/lib/psqlodbc.so
Setup           = /usr/lib/libodbcpsqlS.so
Driver64                = /usr/lib64/psqlodbc.so
Setup64         = /usr/lib64/libodbcpsqlS.so
FileUsage               = 1

[MySQL]
Description             = ODBC for MySQL
Driver          = /usr/lib/libmyodbc5.so
Setup           = /usr/lib/libodbcmyS.so
Driver64                = /usr/lib64/libmyodbc5.so
Setup64         = /usr/lib64/libodbcmyS.so
FileUsage               = 1

[ODBC Driver 11 for SQL Server]
Description             = Microsoft ODBC Driver 11 for SQL Server
Driver          = .platform/vendor/opt/microsoft/msodbcsql/lib64/libmsodbcsql-11.0.so.2270.0
Threading               = 1
UsageCount              = 1

odbc.ini is empty.

Am I missing something?