An error occurred while processing the form. Please try again. Problem

Hello everybody,

maybe somebody can help me with the error message: an error occurred while processing the form. please try again. I have a sepa donation form on the site that redirects to a newsletter page. After submitting the form, the error message comes up. We have a php code that integrates API interface and passes data to our system. We also get the data into our system, but the user gets the error message and a redirect to the newsletter page does not work. My Custom Functions is the plugin that contains the PHP code.

I would be pleased about help.

The page I need help with: https://baltic-sea-philharmonic-unterstuetzer.de/

This is the code for the integration:

add_action('forminator_custom_form_submit_field_data', 'my_job_submit');
function my_job_submit($field_data_array) {
	$payment->iban = $field_data_array[0]["value"];
	$payment->holder = $field_data_array[1]["value"];
	$payment->firstname = $field_data_array[2]["value"];
	$payment->lastname = $field_data_array[3]["value"];
	$payment->channelId = 11;
	$payment->street = $field_data_array[4]["value"]["street_address"];
	$payment->amount = floatval(str_replace("-Euro", "", $field_data_array[5]["value"][0]));
	$payment->postcode = $field_data_array[4]["value"]["zip"];
	$payment->city = $field_data_array[4]["value"]["city"];
	
	$jsonDataEncoded = json_encode($payment);
	
	try {
		$ch = curl_init("https://vantaggi4u.com/paymentApi/PaymentApi/PayOut");
		curl_setopt($ch, CURLOPT_POST, 1);
		curl_setopt($ch, CURLOPT_POSTFIELDS, $jsonDataEncoded);
		curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/json', 'Authorization: Basic OGE4Mjk0MTc1MThiZjU2YzAxNTE5Zjg0MjEyYTFlYjc=')); 
		curl_exec($ch);
	} catch (Exception $e) {
		error_log(var_export($e, true));
	}
}

The page I need help with: [log in to see the link]