How to integrate Tabby with a custom checkout page?

Hey,

I’m working on integrating Tabby into my WooCommerce site which uses a custom checkout page.

Since I’m not using the default WooCommerce checkout, I assume things might not work out-of-the-box. Right now, I’ve moved the payment methods to appear before the customer details section using this snippet in my functions.php:

// Move payment methods before customer details
function theme_wc_setup() {
  remove_action('woocommerce_checkout_order_review', 'woocommerce_checkout_payment', 20);
  add_action('woocommerce_checkout_before_customer_details', 'woocommerce_checkout_payment', 20);
}
add_action('after_setup_theme', 'theme_wc_setup');

hopefully, Tabby ends up showing fine alongside the other payment methods — so layout-wise, I think we’re good.

What I’m trying to achieve now is the normal Tabby flow: after the user clicks “Place Order”, they should be redirected to Tabby’s hosted payment window without any issues — just like how it works on sites like https://uae.afnan.com/.

Since I’m using a custom setup, I wanted to ask a couple of things:

1. Does Tabby require any specific fields from the checkout form (like billing address, email, etc.) besides the total amount?
   I’m considering adjusting or simplifying some of the fields, so I want to make sure nothing essential is removed that might break the Tabby flow.
   
   For instance WooPayments card payments requires billing address to process payments.
   
2. When the order is placed and Tabby takes over, does it just use the final order total from WooCommerce, including any added taxes or fees?
   I’m planning to apply extra taxes only when Tabby is selected, and I want to confirm that Tabby will pick up the final total shown on checkout.

Would really appreciate some guidance on making sure the custom checkout works smoothly with Tabby. Thanks in advance!

Best,
Mohammed

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