UT | Express.js | onUploadComplete doesn't trigger at all

const uploadthing = createUploadthing({
    errorFormatter: (err) => {
        return { message: "Something went wrong, please try again!" };
    },
});

const appRoutes = new Router();

export const uploadthingUploader = {
    imageUploader: uploadthing({
        image: {
            maxFileSize: "512KB",
            maxFileCount: 1,
            minFileCount: 1,
            acl: "public-read",
        },
    })
        .middleware(async ({ req, res, event }) => {
            let token = req.cookies?.token;
            if (!token) {
                token = req.headers?.token;
            }
            if (!token) {
                throw new UploadThingError("unauthorized!");
            }
            const user = genericUtils.decodeJWT(token);
            if (!user)
                throw new UploadThingError(
                    "You must be logged in to upload a profile picture"
                );
            return { userId: user?.userId };
        })
        .onUploadComplete(async ({ metadata }) => {
            console.log(`bro please work ❌`);
            console.log("Uploaded 🔥 by user", metadata);
        }),
};

appRoutes.use(
    "/uploadthing",
    createRouteHandler({
        router: uploadthingUploader,
        config: {
            logLevel: "Error",
        },
    })
);