OTP-Free Global Payment Integration

I need a developer who can help me find and fully integrate a card-processing REST API that works world-wide, handles both one-time and recurring charges, and lets customers keep a card on file so future payments can be completed without any OTP or extra step from the issuing bank.

The core of the job is twofold: first, identify processors or acquirers that actually permit non-3-D-Secure flows for eligible transactions; second, wire the chosen gateway into my application with clear, token-based calls for create-charge, capture, refund, and subscription management. I am open to Stripe, PayPal, Square, or any other platform as long as it reliably supports the “saved card / no additional authentication” requirement across multiple countries.

You will deliver a working integration (test and live keys), concise setup documentation, and a quick demo script that shows:
• a successful one-time charge with no challenge
• a stored-card subscription that renews automatically

Once those two scenarios run end-to-end, the project is complete and I release payment immediately.