How to use conditional fields

Hi,

I need some help with conditional fields… I followed instructions here: https://www.visser.com.au/documentation/woocommerce-checkout-manager/usage/ but I can’t make it works properly.

I need a select field “Do you want Invoice or Receipt?” (required). If the answer is “Invoice” the text field “VAT number” has to show up and be required.

Can you help me?

Thank you!