Stripe integrate into Custom HTML5 Pop-up Modal

We already have a beautiful Pop-Up Modal created to accept donations for a non-profit website. We'd like to integrate this exact modal with Stripe. The site is 100% static - only uses HTML5. If server access is needed, you will create an applet on Azure Web Services - we can give access to one of these if needed. Your job will be to make this function 100% in Sandbox mode. Then, our developer will duplicate your efforts over to the live server. The Github branch this is on is here: [login to view URL] -- We have multiple payment gateways like this that we need to configure with Stripe / Azure. If your price is reasonable & your strategy is clean/optimized - then we will be able to send more work like this your way. Instead of asking us any questions: review the above Git to understand the full project. Though, this is honestly just a simple connection from Stripe to HTML5 & using Azure as the data processor with an applet if needed.