Woocommerce add a text field if specific option is selected

Question

I need to make active/visible a new filed before 'Add to cart' button, only if user select a specific option.

The case is simple: I sell t-shirt with options: "Small", "Medium", "Large", "Size upon request". If user select "Size upon request" I need to know which size needs.

I found some plugin to get this, but they add field in checkout page, I need before add to cart.

Answer 1

SOLVED:
I used the premium plugin "Woocommerce Extra Product Options" (https://themehigh.com/product/woocommerce-extra-product-options)

Thanks