Checking "Provides a file for download" and saving leds to unexpected error

Problem/Motivation

Enable "Provides a file for download" results in "The website encountered an unexpected error. Try again later."

Error: Call to a member function get() on null in Drupal\commerce_license\FormAlter\ProductVariationTypeFormAlter::formValidate() (line 166 of /xxx/modules/contrib/commerce_license/src/FormAlter/ProductVariationTypeFormAlter.php).

Setup:
Drupal Version 10.4.8
Commerce 3.1.0
Commerce File 8.x-2.2
Commerce License 3.0.2

Steps to reproduce

Enable "Provides a file for download" and save in /admin/commerce/config/product-variation-types/default/edit