There is an API documentation, your work is to build a seamless checkout script in one page using PHP client. User enter amount to donate in USD, generate invoice and wallet address for the user, collect payment, validate and store the data in a database mysql table.? The Api require authentication key, you create account and insert your own key. Documentation is here: https://www.luno.com/en/api
php, Ajax, mysql, curl, https
build php bitcoin payment api?