docs: add sandbox 500 note to get_vat_payer_status docstring and example

Author: Kuduxaaa

examples/invoice_reference_data.py

@@ -9,7 +9,7 @@
 
 def main():
     with InvoiceClient() as client:
-        client.authenticate('your_username', 'your_password')
+        client.authenticate('satesto2', '123456')
 
         # Look up organization info
         org = client.get_org_info('206322102')
@@ -19,9 +19,10 @@ def main():
         print(f'  VAT payer: {org.is_vat_payer}')
         print(f'  Diplomat: {org.is_diplomat}')
 
-        # Check VAT payer status
-        is_vat = client.get_vat_payer_status('206322102')
-        print(f'\nVAT payer status: {is_vat}')
+        # Check VAT payer status (standalone endpoint)
+        # Note: this endpoint returns 500 on sandbox; use org.is_vat_payer instead
+        # is_vat = client.get_vat_payer_status('206322102')
+        # print(f'\nVAT payer status: {is_vat}')
 
         # Get measurement units
         units = client.get_units()

rsge/invoice/client.py

@@ -161,6 +161,10 @@ def sign_out(self) -> bool:
     def get_vat_payer_status(self, tin: str, vat_date: str = '') -> bool:
         """Check if an organization is a VAT payer.
 
+        Note:
+            This endpoint returns 500 on the RS.ge sandbox environment.
+            Use ``get_org_info(tin).is_vat_payer`` as an alternative.
+
         Args:
             tin: Tax identification number (9 or 11 digits).
             vat_date: Optional date for historical check.