How would I send a multipart/form-data content-type with Fastify?

[coral zenith]

I spent like half an hour trying to figure out how to respond to a request with a multipart/form-data content-type, but google just keeps showing me results for HANDLING multipart/form-data REQUESTS, I want to RESPOND to a request with a multipart/form-data content-type, NOT handle a request with that content-type. I'm emphasizing my goal heavily considering not only google not giving any helpful answers for what I was asking, but even ChatGPT was giving examples that were for handling multipart/form-data instead of sending it.

[stray elm]

use something like https://www.npmjs.com/package/form-data