How to set Maximum Payload Size on NodeJS App

How do I increase the Maximum Payload Size that a POST request can receive in a NodeJS App running on the App Platform? If this was on Nginx, I would increase the client_max_body_size. How do I do this in an App on Digital Ocean?

More details:

I successfully deployed a SvelteKit app on the App Platform. SvelteKit provides API routes as well as frontend pages. I am sending an image from a frontend page to an API route:

Frontend code:

const imageData = canvas.toDataURL(‘image/png’); const response = await fetch(‘/api/imageTextDetection’, { method: ‘POST’, headers: { ‘Content-Type’: ‘text/plain’ }, body: imageData });

Server Code:

export const POST: RequestHandler = (async ({ request }) => { const imageData: string = await request.text(); … }

In the Browser, I am getting the following error message:

POST https://**** 413 (Payload Too Large) Error sending image to server: Error: Server responded with an error

When running the application locally, this is not giving me any error.