Exiting Tor Browser correctly by command

Question

I am writing a script in bash that automatically starts tor browser by ./start-tor-browser google.com and trace for some time and end the process. After that I start the tor browser again and after some time (almost every 4 restarts) I get an error message that Tor Browser has closed unexpectedly while starting.

Why does it start multiple times normally and then whines about being closed unexpectedly?

This is my code:

create_fingerprint () {
    ./tor-browsers/tor-browser-1/Browser/start-tor-browser "$WEBSITE"
}

while true
do
    PID="$(create_fingerprint)"
    sleep 30
    kill -s firefox TERM
    sleep 10
done

I have tried multiple ways to close the tor browser but it is always failing.

I want to end it gracefully by command line and not by clicking on the red X button.

Thank you very much!