Telephone type switched to string

Author: Sander de Vos

src/Data/RecipientData.php

@@ -14,7 +14,7 @@ class RecipientData extends Data
     public string $to_post_number;
     public string $country;
     public string $country_state;
-    public int $telephone;
+    public string $telephone;
     public string $email;
 
     public array $required = [

src/Data/SenderData.php

@@ -12,7 +12,7 @@ class SenderData extends Data
     public string $from_city;
     public string $from_postal_code;
     public string $from_country;
-    public int $from_telephone;
+    public string $from_telephone;
     public string $from_email;
 
     public array $required = [