Soho Hotel uses WooCommerce to process all payments. First make sure you have installed and activated the WooCommerce plugin. Then go to WooCommerce > Settings > Payments and setup the payment gateways of your choice.
If you're not familiar with WooCommerce I recommend you check out their very detailed documentation here: https://docs.woocommerce.com/
It's important to note that you must set your booking page as the WooCommerce checkout page, or the checkout will not function correctly. To do this go to WooCommerce > Settings > Advanced and set the Checkout page as your booking page.