❔ Can you modify fields in a struct?

I am working on a school project and have run into an issue. Code snippets is: https://sourceb.in/SsaOkq7M8I

This line,

game.quantityInCart++;

game.quantityInCart++;

doesn't actually change the variable. When I print it

Console.WriteLine($"{game.quantity} - {game.quantityInCart}");

Console.WriteLine($"{game.quantity} - {game.quantityInCart}");

it is always 0. Can variables in a struct not be modified ?