Stripe Integration for PHP Web-Based App

I need a professional with a deep understanding of Stripe, to integrate it into my third-party web application. The main purpose of this integration is to enable online payments on my platform.

The instructions:
My webapp uses a webservices API for some admin and user tasks. The command for updating a users credit in my app is "http://api.expresstxtapp.com/index.php?app=ws&h=%3Cwebservicetoken%3E&u=%3Cadmin%3E&op=creditadd&data_username=%3Cuser%3E&data_amount=%3Camount%3E". Create a billing page/form so that when the user goes to pay the link will update to use the users username for the data_username parameter and the amount they payed into the data_amount parameter and then stripe will handle the payment and once the payment is complete will update the users credit in the app using the webservices API.

Skills and Experience Required:
- Strong experience in Stripe API integration
- Familiarity with web-based applications
- Proven track record of implementing online payment solutions

Job Details:
- The integration should allow for one-time payments
- The freelancer must test and verify the successful implementation of the Stripe integration