Help - how does multipart works under the hood

## 💬 Question here

How does `@fastify/multipart` work?
I'm trying to upload a file approximately 20-50 mib size.
I'm planning on using multipart as a content type, so I used `@fastify/multipart`.
But, I have `nginx` reverse proxy, so I'm limited to 1mb to the request size.
My question is does multipart send the data in chunks? does it do that for me? my testing saying it doesn't, but just wanted to ask to make sure.

- *node version*: 22
- *fastify version*: 5.1.0
- *os*: Linux