Integrate OXXO PAY with Conekta to React SPA and Paypal

I have a chatbot that have to accept payments so i'm making a webview with Two Payments methods. Paypal ( Paypal and Credit Debit Cards with Paypal) OXXO Pay (Using [login to view URL]) to accept payments from OXXO in México. It's not complicated, i only want a single webview that show Three buttons with the payment methods and when people pay show with [login to view URL]('Payment success') I'm Deploying it with Firebase Hosting and Firebase Functions Who can do it with low budget?