[Hyva] Undefined array key "houseNumber"

[martin-cod]

🪲 Describe the bug
The following error is in error logs

[2025-08-13T06:38:07.313450+00:00] report.CRITICAL: Form modifier "Exception" threw an exception: Warning: Undefined array key "houseNumber" in vendor/hyva-themes/magento2-hyva-checkout-postcodenl/src/Model/HyvaCheckout/Form/EntityFormModifier/PostcodeNL/WithDutchPostcodeHouseNumberCombination.php on line 259 {"exception":"[object] (Exception(code: 0): Warning: Undefined array key \"houseNumber\" in vendor/hyva-themes/magento2-hyva-checkout-postcodenl/src/Model/HyvaCheckout/Form/EntityFormModifier/PostcodeNL/WithDutchPostcodeHouseNumberCombination.php on line 259 at vendor/magento/framework/App/ErrorHandler.php:62)"} []

🔄 To Reproduce
Have no exact steps, just see erorr in exception.log

✅ Expected behaviour
No exceptions thrown

⚙️ Environment

• Magento version and edition: Adobe commerce 2.4.6-p11
• hyva-themes/magento2-hyva-checkout-postcodenl version 1.1.1

[JerrySmidt]

This module doesn't support the Hyvä Checkout. See also #96