script execution error

Question

I am trying to run my script which checks for a file existence and validates its records. If validation is successful it uploads the input file to database.`

While executing the script ,it loads the file to table but displays below errors and successful completion part is not echoed.Below is my execution output.

./GIC.sh[3]: RETAIL_PATH:  not found
./GIC.sh[4]: DB_LOGIN:  not found
./GIC.sh[10]: INPUTFILE:  not found
./GIC.sh[14]: test: argument expected
./GIC.sh[20]: test: argument expected
Thu Jul  8 07:00:53 2021 run SQL*LOADER for
SQL*Loader: Release 18.0.0.0.0 - Production on Thu Jul 8 07:00:53 2021 Version 18.4.0.0.0
Copyright (c) 1982, 2018, Oracle and/or its affiliates.  All rights reserved.
Path used:      Conventional Commit point reached - logical record count 11
Table GIC_TERMR_STG: 9 Rows successfully loaded.

My code is as below:

#!/bin/sh
RETAIL_PATH =/central
DB_LOGIN =/@RETAIL_CENTRAL
CTLFILE=$RETAIL_PATH/sld/GIC_termr.ctl
LOGFILE=$RETAIL_PATH/log/sld/GIC_termr.log
BADFILE=$RETAIL_PATH/log/sld/GIC_termr.bad
INPUTFILE = $RETAIL_PATH/bin/sample.txt
SUPPORT_EMAIL="valarmathi.pauldurai@bmo.com"
if [ ! -f $INPUTFILE ]; then
pecho " Cannot find the Input file :$INPUTFILE "
fi
#Inputfile check
if [ ! -f $INPUTFILE ]; then
pecho "can't find SQLLoader Input file $INPUTFILE"
mailx -s "cannot find input file $INPUTFILE" $SUPPORT_EMAIL
exit 0
fi
pecho "run SQLLOADER for $INPUTFILE"
sqlldr $DB_LOGIN control=$CTLFILE log=$LOGFILE bad=$BADFILE
tmp_var1=$?
if [ $tmp_var1 -eq 0 ]; then
pecho "Sucessful completion"
else
pecho "SQL*Loader log file in $SLDLOG"
echo "Please refer to $RETAIL_PATH/log/sld/${BADFILE}.bad and ${LOGFILE}." | mailx -s "subj XXX" "${SUPPORT_EMAIL}"
fi
exit 0