How to Properly Remove Facetime on MacBook

you can't delete them, they live on the protected system volume. 

Thank you! Can we at least block this app from being used?

You can also use a script to remove those apps and any others from the dock. Outta sight, outa mind type thing. The scrip below will remove everything from the dock and replace it with whatever you specify. There are probably better/slicker scripts out there, but this one works just fine for me.

# Don't do anything until the Dock has started
if [[ ! $(pgrep -x Dock) ]]; then
until [[ $(pgrep -x Dock) ]]; do
echo "Dock not started. Waiting 1 second..."
sleep 1
done
echo "Dock started at: $(date +"%r")"
else
echo "Dock already started"
fi

USERNAME=$(/bin/ls -l /dev/console | /usr/bin/awk '{ print $3 }')
dockutil="/usr/local/bin/dockutil"

#remove stuff
sudo -u $USERNAME $dockutil --remove all --no-restart --allhomes

#add stuff
sudo -u $USERNAME $dockutil --add '/Applications/Microsoft Outlook.app' --no-restart --allhomes
sudo -u $USERNAME $dockutil --add '/Applications/Google Chrome.app' --no-restart --allhomes
sudo -u $USERNAME $dockutil --add '/Applications/Microsoft Teams.app' --no-restart --allhomes
sudo -u $USERNAME $dockutil --add '/Applications/Microsoft Excel.app' --no-restart --allhomes
sudo -u $USERNAME $dockutil --add '/Applications/Microsoft Word.app' --no-restart --allhomes
sudo -u $USERNAME $dockutil --add '/System/Applications/System Settings.app' --no-restart --allhomes
sudo -u $USERNAME $dockutil --add '/Applications/Self Service.app' --no-restart --allhomes

#add folders
#Example of how to add a folder - sudo -u $USERNAME $dockutil --add '/Applications/' --no-restart --allhomes
#Example of how to add a folder - sudo -u $USERNAME $dockutil --add '~/Downloads/' --no-restart --allhomes
#Example of how to add a folder - sudo -u $USERNAME $dockutil --add '~/Documents/' --no-restart --allhomes

#kill Dock
sudo killall Dock

You also don't need to use a script to Add/Remove items from the dock.
Just add them as Dock items under Settings>Computer Management>Dock Items and then you can manage them with the dock items payload in a standard policy

This worked great, thank you!