UI mode 'custom' is not working when creating checkout session

[mirkoappy]

Cashier Stripe Version

16.0.1

Laravel Version

12.8.1

PHP Version

8.4.4

Database Driver & Version

MySQL Ver 8.4.4 for Linux on aarch64 (Source distribution)

Description

Laravel Cashier doesn't not support ui_mode set to custom. It handles that as hosted mode.

Issue seems to be with create method in Checkout class with the code:

if (isset($data['ui_mode']) && $data['ui_mode'] === 'embedded') {
    $data['return_url'] = $sessionOptions['return_url'] ?? route('home');

    // Remove return URL for embedded UI mode when no redirection is desired on completion...
    if (isset($data['redirect_on_completion']) && $data['redirect_on_completion'] === 'never') {
        unset($data['return_url']);
    }
} else {
    $data['success_url'] = $sessionOptions['success_url'] ?? route('home').'?checkout=success';
    $data['cancel_url'] = $sessionOptions['cancel_url'] ?? route('home').'?checkout=cancelled';
}

It should be changed to:

if (isset($data['ui_mode']) && ($data['ui_mode'] === 'embedded' || $data['ui_mode'] === 'custom')) {
    $data['return_url'] = $sessionOptions['return_url'] ?? route('home');

    // Remove return URL for embedded UI mode when no redirection is desired on completion...
    if (isset($data['redirect_on_completion']) && $data['redirect_on_completion'] === 'never' && $data['ui_mode'] === 'embedded') {
        unset($data['return_url']);
    }
} else {
    $data['success_url'] = $sessionOptions['success_url'] ?? route('home').'?checkout=success';
    $data['cancel_url'] = $sessionOptions['cancel_url'] ?? route('home').'?checkout=cancelled';
}

Steps To Reproduce

Try to initiate checkout with

$checkout = $user->checkout(['price_1SC...'], [
    'ui_mode' => 'custom',
    'return_url' => $this->returnUrl,
]);

If you have no 'home' route defined it will throw an error "Route [home] not defined."
If there is 'home' route defined, it will throw an error "The following parameters are not supported with 'ui_mode: custom': cancel_url, success_url."

Expected behaviour would be to return Stripe session object.