Action for the Thank you page

Hello,

We are working on some improvements of our custom WooCommerce theme and want to make some changes of the thank you page. And we found that there is no action at the beginning of the file like for example checkout and cart pages have (checkout/form-checkout.php – woocommerce_before_checkout_form action (https://prntscr.com/k5ydqs
), cart/cart.php – woocommerce_before_cart action (https://prntscr.com/k5ydy8
))
Could you, please, add the similar action for the thank you page (checkout/thankyou.php, https://prntscr.com/k5ydes)?

Waiting for your reply.
Thanks.

Regards