How to execute an exit function before closing rebar3 shell?

Question

I have a rebar3 app with a supervisor and some modules I want to execute a function before aborting the shell

I have tried adding an exit function in the supervisor,but its not working.I wanted to know if that's possible and if yes if I could have some examples that'd be great thank you.

I tried something like this but its not working

-module(shell_termination).
-export([start/0]).

start() ->
    GracefulStopPid = spawn(fun graceful_stop/0),
    process_flag(trap_exit,true),
    register(gracefulStop, GracefulStopPid),
    receive
        shutdown ->
            io:format("Application stopped gracefully~n"),
            erlang:halt()
    end.

graceful_stop() ->
        process_flag(trap_exit,true),

                io:format("Graceful stop process received shutdown signal~n"),

    receive
        shutdown ->
            io:format("Graceful stop process received shutdown signal~n"),
            exit(normal);
            _->
            io:format("Graceful stop process received shutdown signal~n")
    end.


erlc shell_termination.erl 
kaushik@kaushik-ThinkPad-E15-Gen-2:~/erlang$ erl
Erlang/OTP 26 [erts-14.1] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1] [jit:ns]

Eshell V14.1 (press Ctrl+G to abort, type help(). for help)
1> shell_termination:graceful_stop().
<0.88.0>
2> 
BREAK: (a)bort (A)bort with dump (c)ontinue (p)roc info (i)nfo
       (l)oaded (v)ersion (k)ill (D)b-tables (d)istribution
a