My environment
[Svelte] --FormData submit--> [SvelteKit Endpoint] --call for save file --> [Rails]

Describe the issue

I uploaded the file and submitted the form to the SvelteKit Endpoint. Then I passed FormData from SvelteKit to Rails by Axios get error "Data after transformation must be a string, an ArrayBuffer, a Buffer, or a Stream"

Example Code

Code snippet to illustrate your question

[svelte]
<form
    on:submit
    method="post"
    enctype="multipart/form-data"
    action="/api/reports"
>
   <Fileupload name="report[thumbnail]" size="sm" accept="image/png, image/jpeg" />
</form>

[sveltekit endpoint]
export const POST: RequestHandler = async ({ request, locals }) => {
    const form = await request.formData();    // get formData
    const response = await axios.post(`${url}`, data) // send form data
};

Expected behavior, if applicable

I think can send FormData value to Rails server

Environment

"axios": "^0.27.2",
"@sveltejs/adapter-node": "1.0.0-next.88",
"@sveltejs/kit": "next",

Additional context/Screenshots