Edit invoicing plugin (Woocommerce) -- 2

Job ID: 32823546

Budget: $10 – $30 USD

I need to edit an invoicing plugin that is not working in 3 different cases:
- Order has discount
- Order has an additional checkout amount
- Invalid customer DNI

I need to create conditions to make it work on these cases.
Related categories: PHP WordPress Software Architecture HTML WooCommerce