PayPal Subscriptions APIs Integration

[AssafMalki]

Hey,

I try to integrate the Subscriptions API to my website.

First of all, I'm not sure if I should use this API or the billing agreement API, all I want is to bill my costumers with a fix amount each month...

Anyway,

I have created a product, a plan and a subscription,

At the end I got an id (I-2PR5ANJT6J4C)

I try to use this id in the PayPal button:

<script src="https://www.paypal.com/sdk/js?client-id=sb&currency=ILS"></script>
<script>paypal.Buttons({
    style: {
        shape: 'pill'
    },
    env: 'sandbox', // Or 'production'
    // Set up the payment:
    // 1. Add a payment callback
    createOrder: function(data, actions) {
        // 2. Make a request to your server
        return new Promise(function(resolve) {
            return resolve('I-2PR5ANJT6J4C');
        })
    },
    // Execute the payment:
    // 1. Add an onAuthorize callback
    onAuthorize: function(data, actions) {
        // 2. Make a request to your server
        return actions.request.post('/my-api/execute-payment/', {
            paymentID: data.paymentID,
            payerID:   data.payerID
        })
            .then(function(res) {
                // 3. Show the buyer a confirmation message.
            });
    }
}).render('#paypal-button-container');</script>

And I got this error:

Uncaught Error: I-2PR5ANJT6J4C does not match pattern for order-id, ec-token or cart-id

Anyone else faced this issue? How can I pass the subscription id to the button to work correctly?

Thanks,

Assaf