File: /applications/nexus/sources/Gateway/Stripe/Stripe.php
Line 501 opens an if statement:
if ( \in_array( $settings['type'], array( 'alipay', 'bancontact', 'giropay', 'ideal', 'sofort' ) ) and !isset( $values[ $this->id . '_card' ] ) )
Within this if statement if found true on line 538, the application is instructed to use the deprecated sources API:
$response = $this->api( 'sources', $data );