sample.js

const lib = require('lib')({token: process.env.STDLIB_SECRET_TOKEN}); // guessing this initializes stripe-node, and should be your platform's secret key, not the connected account's.
const pug = require('pug');
const render = pug.compileFile('./payment.pug')

/**
* An HTTP endpoint that acts as a webhook for Custom API or Webhook request event
* @returns {object.http} result Your return value
*/
module.exports = async (amount=null, frequency=null, email=null, firstname=null, lastname=null, street=null, zip=null, city=null, state=null, cellphone=null, occupation=null, employer=null) => {
  const fec = {
    amount,
    frequency,
    email,
    firstname,
    lastname,
    street,
    zip,
    city,
    state,
    cellphone,
    occupation,
    employer
  };
  const stripe = await lib.stripe.paymentintents['@0.0.1'].create({
    amount: amount * 100,
    currency: `USD`,
    confirm: false,
    description: `Donation: Every Two Years`,
    metadata: JSON.parse(JSON.stringify(fec)),
    receipt_email: email,
    statement_descriptor: `Every Two Years`,
    capture_method: 'automatic',
    confirmation_method: 'automatic',
  }, {
    stripeAccount: "acct_connectedStripeAccountID", // add
  });
  return {
    headers: {'Content-Type': 'text/html'},
    statusCode: 200,
    body: Buffer.from(render({
      stripeKey: process.env.stripe_key, // guessing this might be the connected account's secret key, but you likely want this to be your platform secret key, and then you also likely want to send the ID of the connected account to the client, too.
      clientSecret: stripe.client_secret,
      name: `${firstname} ${lastname}`,
      amount
    }))
  };
};