PayPal Flexible Payment Portal & Subscription Setup

I already have a verified PayPal developer account and now need the entire PayPal Subscriptions flow built through the REST API so I can drop it straight into my WordPress site
—no off-the-shelf plugin, just clean API work.

Here is what I expect:

• A fully configured PayPal app in Sandbox and Live, covering Products, Billing Plans, and Subscriptions. I also want the PayPal app to remain under my PayPal Developer account.
• Secure OAuth flow set up (client ID / secret) with the correct scopes.
• Webhooks created and tested for all key events (activation, payment, pause, resume, cancel, plan change, payment-cycle extension).
• Sample curl / PHP / JS calls that clearly show how to create, update, pause, resume, cancel, and switch plans so I can adapt them in WordPress.
• Clear hand-over documentation: API endpoints, headers, webhook listener example, and any parameters I must store.
• Confirmation that the same flow works end-to-end in Live after Sandbox testing.

Everything should be tested inside the PayPal Sandbox first, then promoted to Production once I can verify on my side.

Deliverables will be accepted when:
1. I can trigger each subscription action from your sample calls and see the corresponding webhook fire.
2. Switching a subscriber from one plan to another, as well as pausing, resuming, cancelling, and extending billing periods, all complete without errors.
3. Credentials, endpoints, and a concise setup guide allow me to recreate the integration within my WordPress dashboard.

If you have deep PayPal REST/Subscribers experience and can walk me through the final verification call, let’s get started.

Target Project Price about $100 - 150 USD