I have the following code:

//On server /app/api/findPartsFittingMachine/route.js

const mysql = require('mysql2/promise');

export async function GET(request) {
    try {
        //Create connection request
        let conn = await mysql.createConnection({
            host: process.env.ATCREVIVE_DB_HOST,
            user: process.env.ATCREVIVE_DB_USER,
            password: process.env.ATCREVIVE_DB_PASSWORD,
            database: process.env.ATCREVIVE_DB_MAINDB
        });

        //Get the part number from the search parameters
        const searchParams = request.nextUrl.searchParams;
        const partNumber = searchParams.get('partNumber');

        //Create a query to get all columns from part entries with a matching part number
        let query = `SELECT * FROM Part_Entries WHERE number='${partNumber}'`;

        //Execute the query
        const [results] = await conn.execute(query);

        //Disconnect from the database
        conn.end();

        //Return the results in a response
        return new Response.json({results});
    }
    catch (err) {
        return new Response({ error: err },
            {
                status: 500
            });
    }
}

And

//On server component /app/parts/[slug]/page.js
export async function getData() {
    const apiURLEndpoint = `http://localhost:3000/api/findPartsFittingMachine?partNumber=17255-046-010`;
    const response = await fetch(apiURLEndpoint);
    const res = await response.json();
    return res;
}

export default async function Page({ params }) {

    let data = await getData();

    return <h1>Test</h1>
}

I see this same concept on both the NextJS docs, and this video here (https://www.youtube.com/watch?v=aprLiG34b50&t=705s, skip to 9:00).

This works well on their demonstrations, but when I do it, it tries to return [Object object] and I get the error:
SyntaxError: "[object Object]" is not valid JSON
Do I have to stringify the data and mess with it to get it to work?