braintree.paypalCheckout.create add dynamical amount to the paypal button - paypal

Question

I use HostedFields for credit card and paypal web for paypal.
So inside of braintree.client.create i have braintree.hostedFields.create and braintree.paypalCheckout.create.
Code example of paypal:
braintree.paypalCheckout.create({
client: clientInstance
}, function (paypalCheckoutErr, paypalCheckoutInstance) {
if (paypalCheckoutErr) {
console.error('Error creating PayPal Checkout:', paypalCheckoutErr);
return;
}
paypal.Button.render({
env: 'sandbox',
commit: true,
buttonStyle: {
color: 'blue',
shape: 'rect',
size: 'medium'
},
payment: function () {
return paypalCheckoutInstance.createPayment({
flow: 'checkout',
locale: ''+langanalytics+'',
amount: '10.00',
currency: 'EUR'
});
},
onAuthorize: function (data, actions) {
return paypalCheckoutInstance.tokenizePayment(data, function (err, payload) {
document.getElementById("paynonce").value = payload.nonce;
document.getElementById("paymentform").submit();
});
},
onCancel: function (data) {
console.log('checkout.js payment cancelled', JSON.stringify(data, 0, 2));
},
onError: function (err) {
console.error('checkout.js error', err);
}
}, '#paypal-button').then(function () {
});
});
The problem is according to my client he want a single page checkout, where the amount get generated dynamically.
For example if someone change the country or payment method the price can change for some €. A click EventListener start the calculation and changes the total sum in real time.
My Problem:
I cant change the amount of my paypal intialization of this part:
return paypalCheckoutInstance.createPayment({
flow: 'checkout',
locale: ''+langanalytics+'',
amount: '10.00',
currency: 'EUR'
});
Is there any way to update the amount outsite of the function as soon as total sum changes (i have full control of this).
I already tried to intialize the whole braintree.client.create new on total sum change but i get errors from hosted fields a instance is already created and for paypal i recieve multiple buttons.