The Purchase event works on the default WooCommerce’s “Thank You Page” (order-received).
If you want to use custom thank you pages, you will have to use our dedicated add-on, part of the Super-Pack. It will let you define a global thank you page, or per product thank you pages.
The plugin follows WooCommerce’s settings in order to fire each specific event. Because of this, you must keep the original Checkout settings (your pages names might be different):
If you want to redirect the cart page to the checkout page, you can do it by adding a 301 redirect on the cart page. A dedicated redirect plugin can help – there are a few free ones in the WordPress repository.