Hi PARISI TOUR ,
Thank you for your purchase.

1.

At the moment the solution would be to use the coupons but you will need to add a coupon and send to all of the customers. Setup of coupons are based on service, and the plugin can not know which payment method will be used.

There is no other way to achieve this because we can not know which payment method will be used for the coupon.

2.

You can use hooks like beforeConfirmedBooking or afterConfirmBooking that will be triggered when your customers confirm booking. You can set that redirect URL that you need like on this script (we use https://www.google.com as example, but you will replace this with your own URL)

<script>
window.beforeConfirmedBooking = function()
{
window.location.href = "https://www.google.com";
};
</script>

Please insert this script on page where you insert Amelia shortcode.

Best regards.