Paypal balance not showing in my subscription button options

[AndreiSirbu]

Hello,

I've followed this guide to create a paypal subscription button:

https://developer.paypal.com/docs/subscriptions/integrate/

All works ok, but the user doesn't get the option to choose the paypal balance as an option, only creditcards are present.

These are the additional options I've set:

             'application_context ': {
                        'payment_method': {
                            'payer_selected': 'PAYPAL'
                        }
                    }

What do I need to do to also show the paypal balance as an option?

Thanks.