sudo apt update
sudo apt install rsnapshot

Plug In External Drive:

Now Let's Run The Following Command:
It Will Show The Name Of The Drive:

ls /media/pi/

Now Let's Edit The Config:

sudo nano /etc/rsnapshot.conf

Save File When Done

Let's Test Things Out:

rsnapshot configtest

Time To Backup The Pi:

sudo rsnapshot alpha

To Set Up Auto Backups:

crontab -e

Add The Following At The Bottom Of The File:

30 08 * * * /usr/bin/sudo rsnapshot alpha

Save File When Done

rsnapshot.conf File:

###########################
# SNAPSHOT ROOT DIRECTORY #
###########################

# All snapshots will be stored under this root directory.
#
snapshot_root   /media/pi/1E03-203D   <<<<<-----UPDATE PATH


###############################
### BACKUP POINTS / SCRIPTS ###
###############################

# LOCALHOST
backup  /home/          localhost/    ADD OR REMOVE # AT THE BEGINNING 
#backup /etc/           localhost/    ADD OR REMOVE # AT THE BEGINNING
#backup /usr/local/     localhost/    ADD OR REMOVE # AT THE BEGINNING