Shipping – Pay by invoice

I use very basic shipping method where the customer chooses their items and then completes the order without choosing a shipping method, other than pay with invoice. I would like an option on the shipping where it just states Pay by Invoice and doesn’t reflect a shipping fee, as we then create an invoice and dispatch the invoice with the package.

I would be most grateful for any code to add perhaps on the child theme?

https://www.ads-software.com/plugins/woocommerce/