PHP Laravel- Paypal payment for services(not items) using API call without(skipping) login screen

I have used Paypal Express Checkout successfully with shopping carts and custom Laravel projects.

But this time I want to integrate Paypal in to an API project developed in PHP(Laravel) that collects payments for services(item renting). Since there are many options with Paypal I'm bit confused.

This is the client's requirement: The API project receives a payment request from a mobile app(when a user hand over the rented item and click a button to approve the payment request he receives on his mobile app). When the API code received the above payment request from user's mobile app, API code should be able to call Paypal and process the payment(transfer the payable amount from user/payer account to payee account). The items are rented only to registered users and the API code have access to user info. Therefore API code need to process payment without prompting Paypal login screen(requiring users to enter their Paypal credentials again). In a nut shell, mobile app registered user should be billed only by clicking the above payment approve button.

I know storing Paypal credentials in API project's database is not an option.

• Is this possible/allowed with Paypal? Specially with Paypal Express Checkout?
• Is this requirement relates to Paypal Subscriptions Payments?
• What is the best Paypal solution to use in this scenario?

Pardon me if this question is too specific/localized.

via Chebli Mohamed