Why is my Shopify app proxy sending an empty body?

Technical Q&A
1

I’ve been setting up a Shopify app that needs to make an API call from some information entered on custom fields on the cart page from a store.

I have the app proxy working & pointing to the Node Express route. The console.log inside is firing.

app.post("/requestEndpoint", async(req,res) => {

  console.log(req)
  const { body } = req;
  console.log('Successful')
  let status = 200
  let error = null
  console.log(body)

res.status(200).send({success: status === 200, error})
});

22:30:25 │ web-backend  │     'x-shopify-client-ip-sig': 'fkWXIScWz0W4g/3Lml7JmiYZ6vk=',       
22:30:25 │ web-backend  │     'x-shopify-request-timing': 'cf;t=1692325825.526'
22:30:25 │ web-backend  │   },
22:30:25 │ web-backend  │   [Symbol(kHeadersCount)]: 84,
22:30:25 │ web-backend  │   [Symbol(kTrailers)]: null,
22:30:25 │ web-backend  │   [Symbol(kTrailersCount)]: 0
22:30:25 │ web-backend  │ }
22:30:26 │ web-backend  │ Successful
22:30:26 │ web-backend  │ {}

This is the request

const options = {
      method: 'POST',
      headers: {
        accept: 'application/json'
      },
      body: JSON.stringify({
        pickup: {
          address: {
            state: 'ON',
            country: 'CA',
            street: '123 MAPLE STREET,
            city: 'TO',
            zip: 'M9W9W9'
          })
}

 fetch('/apps/proxy/requestEndpoint', options)
.then(response => response.json())
.then(response => console.log(response))
.catch(err => console.error(err));

The body from my fetch appears to be getting stripped away by the app proxy.