Dash app blocked on authentication

i added basic authentication to my dash app , problem is at start up app is blocked as in the screenshot:

code used:

# Initialize app with a Bootstrap theme
app = dash.Dash(__name__, external_stylesheets=[dbc.themes.BOOTSTRAP]) #external_stylesheets=[dbc.themes.CYBORG]) #
# auth = dash_auth.BasicAuth(
#     app,
#     VALID_USERNAME_PASSWORD_PAIRS
# )
USER_PWD={
    "username":"password",
    "hello":"world2024",
}
BasicAuth(app, USER_PWD)

i don’t understand why is this happening ?