Changing the payment method from the gateway on the website to the external PayU - website on wix.com

I need to add a payu payment system in the form of a redirection to the payu page (with a blik, transfers, etc.) currently in the wix.com system I only have the option of connecting my payu to the gate on the website and customers have to enter their bank card details.

I want to save the current version of the website so that if necessary, for example in case of failures, to be able to restore the old version.

The website is currently online and is selling products, so I would like the work to take place in the background with the possibility of continuous operation of the website.