Take backup of schema using data pump utility ,,, just you need to pass schema name.

Just input schema name and it will take backup of schema.

vi backup_schema.sh

 #!/bin/sh

# Set environment variables

export ORACLE_SID=testdb1

export ORACLE_HOME=/u01/app/oracle/product/12.2.0.1/test-db

export PATH=$PATH:$ORACLE_HOME/bin:$ORACLE_HOME/lib:/usr/ccs/bin:$ORACLE_HOME/OPatch

DATEFORMAT=`date +%Y%m%d`

# Check if schema name is passed as an argument

if [ -z "$1" ]; then

  echo "Schema name is required. Exiting..." >> nohup.out

  exit 1

fi

# Assign the first argument as the schema name

schema_name=$1

# Data Pump export command

echo "Starting backup for schema $schema_name at $(date)" >> nohup.out

expdp \"/ as sysdba\" directory=OBACKUP dumpfile=expdp_${schema_name}_`echo $DATEFORMAT`.dmp logfile=expdp_${schema_name}_`echo $DATEFORMAT`.log schemas=$schema_name parallel=8 cluster=n flashback_time=systimestamp >> nohup.out 2>&1

# Check if the expdp command was successful

if [ $? -eq 0 ]; then

  echo "Backup of schema $schema_name completed successfully at $(date)." >> nohup.out

else

  echo "Backup failed for schema $schema_name. Please check the log file for details." >> nohup.out

  exit 1

fi

Use below command to run the script ...

nohup ./backup_schema.sh schemaname &