Payment Issue

please I need advice regarding adding payment. I want to accept payment on my website but I want the payment to be made on my second website.
Example. I have a wallet on website ‘A’ and I want to top-up my wallet on Website ‘B’ (when the user wants to top up his wallet on website ‘A’, He should be redirected to Website ‘B’ to complete the purchase and will get the Value automatically Added to his Wallet in Website ‘A’ after successful purchase on Website ‘B’. if there is any plugin that does this please let me know, any advice is welcome.

The page I need help with: [log in to see the link]