Stripe API error - "Received unknown parameter: source" - api

Question

Creating subscription site in wix code. I keep getting a 400 unknown parameter: source error. (/subscripton)
if you can spot where i am going wrong it would be appreciated. thanks!
import { fetch } from 'wix-fetch';
export async function subscription(token, item) {
const cart = item;
const apiKey = "PRIVATEAPI";
const response = await
fetch("https://api.stripe.com/v1/subscriptions", {
method: 'post',
headers: {
"Content-Type": "application/x-www-form-urlencoded",
"Authorization": "Bearer " + apiKey
},
body: encodeBody(token, cart)
});
if (response.status >= 200 && response.status < 300) {
const ret = await response.json();
return { "chargeId": ret.id };
}
let res = await response.json();
let err = res.error.message;
let code = res.error.code;
let type = res.error.type;
return { "error": err, "code": code, "type": type };
}
function encodeBody(token, cart) {
let encoded = "";
for (let [k, v] of Object.entries(cart)) {
encoded = encoded.concat(k, "=", encodeURI(v), "&");
}
encoded = encoded.concat("source=", encodeURI(token));
return encoded;
}

Answer 1

welcome to StackOverflow!
It looks like you're creating a Subscription. According to the API docs: https://stripe.com/docs/api/subscriptions/create?lang=ruby
customer is a required parameter when creating subscriptions on Stripe. You would need to create a Customer first, attaching a tokenized card to the Customer as a source. Then, you can create a subscription, by passing customer: customer.id
Also, is this request being made client-side? Requests made with your secret API key should be made from your server-side code and preferably using Stripe's API libraries: https://stripe.com/docs/libraries
Since you're using Subscriptions, you should also look into the new version of Stripe Checkout (https://stripe.com/docs/payments/checkout), it allows creating subscriptions with client-side code with just a few lines of code!

Answer 2

You're likely passing additional keys that you're not expecting to when you call encodeBody(token, cart).
You should verify that the keys you're passing in token and cart are all valid according to the documentation at https://stripe.com/docs/api/subscriptions/create.