Local JavaScript not working as expected

I have this simple Dash application:

import dash
import dash_bootstrap_components as dbc
import dash_core_components as dcc
import dash_html_components as html

app = dash.Dash(
    __name__,
    server=server,
    routes_pathname_prefix='/dashboard/',
    external_stylesheets=[dbc.themes.DARKLY],
    external_scripts=[
        {
            'src': 'https://code.jquery.com/jquery-3.5.1.slim.min.js',
            'integrity': 'sha256-4+XzXVhsDmqanXGHaHvgh1gMQKX40OUvDEBTu8JcmNs=',
            'crossorigin': 'anonymus'
        }
    ]
)

app.layout = html.Div(
    id='big-app-container',
    children=[
       html.Div(
            id='banner',
            className='banner',
            children=[
                html.Div(id='banner-text', children=[html.H3('DAntE')]),
                html.Div(id='banner-session',
                    children=[
                        html.Span(id='session-info'),
                        html.Button('Login', id='session-btn'),
                        html.Button('Sign Up', id='signup-btn')
                    ]
                )
            ]
        )
    ]
)

And the following JS file (assets/dash.js):

$('#session-btn').click(function(){
    console.log('ya');
});

Well, I click the corresponding button, but nothing happens. I don’t know why, because it apparently loads the script. In fact, if I write down the function on Chrome’s console, then it works as expected.

I really need help with this, please