Change amount dynamically problem

[digitalideafi]

Hi, in a php file I create a checkout service with let's say 10€, then I mount the SumUpCard using javascript call (in the same page) with parameters "amount: 50", "currency: EUR" and "locale: it-IT". In the widget, the submit button text is "Pay 10€" but if I make the payment I will pay 50€.
Why the button text do not change? I tried to use showAmount=false but nothing changed.

PHP

$sumup = new SumUp(array(
        'app_id'     	=> "XXXXX,
        'app_secret' => "YYYYY
        'grant_type' => 'client_credentials',
        'scopes'	=> array('payments', 'transactions.history', 'user.app-settings', 'user.profile_readonly'),
));
$returnURL         = "my return url";
$accessToken 	= $sumup->getAccessToken();
$value 			= $accessToken->getValue();
$ckoutsService = $sumup->getCheckoutService();
 $response 	= $ckoutsService ->create(10, "EUR", $value, 'matchenjoy-test@sumup.com', "some text",
          null, $returnURL, "M4FGYHE4", $returnURL);
$checkoutId     = $response->getBody()->id;

JS

currSumUpCARDPren = SumUpCard.mount({
	id: 'sumup-card',
	checkoutId: <?php echo $checkoutId ?>,
	locale: "it-IT",
	currency: "EUR",
	amount: 50,
	showAmount: false,
        onLoad: function() { },
        onResponse: function(type, body) {...}
});