To implement this process you will need either:
Register Merchant Account
Use the Sandbox environment when testing your app, then switch to Live when you are ready to accept real payments.
When the user clicks the Purchase button, data is retrieved from your Safe Activation account. That determines what data fields are collected from the Buyer, what items are available for purchase and what payment options are presented.
The customer can order one or more items. You control the quantity limit of each item that can be purchased. Each item can add optional shipping or tax. The customer can pay with a Credit Card, a Paypal payment or both.
Setup Purchase Process
A Purchase button is associated with a Serial Number activated product that has been setup using QuickLicense or Cloud License (for ExcelRT mobile apps).
Since the entire purchase process is configured from your Vendor account on Safe Activation, you can dynamically add or remove items, change prices, collect additional data from the Buyer, etc. without updates to your product installed on the customer computer.
From the Vendor Info page, locate the Paypal Merchant InApp Purchases section. Enter your Product ID and click Edit Purchase Button.
If the payment is used to enable advanced features within the app itself, the purchase can enable a feature flag. Feature flags are supported by QuickLicense and Cloud License.
Feature flags offer many advantages including portability across applications using the same license, across machines when a license is moved and to multiple computers activated with the same Serial Number. Videos are available that demonstrate how to purchase and use feature flags.
If a purchase requires some type of delivery process or enables capabilities on a website, then use a Webhook to transfer purchase data to your website for additional processing. See the online video for a demonstration.