#Unable to add attachments in InteractionType.APPLICATION_COMMAND — Page 1

Hi there! I am new to creating Discord bots and recently followed the https://discord.com/developers/docs/getting-started tutorial, which uses discordJS with an interactions endpoint URL where Discord will send HTTP Requests and you return something of the form res.send(...). I am trying to do the following: respond with a local video file attached when a user does the /get-video command.
I've looked through all of the attachments documentation but have not been able to find an answer. I do NOT want this in an embed, just want it to be a good old attachment
Some more details

The video file is saved in the same place as my app.js where the code below lives, so the file path is "video.mp4"
My JS type is module, since I adapted it from the getting started tutorial, but I'm open to suggestions on refactoring my code to make it easier
Right now, the bot will respond to my "/get-video" command, but it doesn't include the embed

Here is my code so far which does respond but fails to add an attachment
`if (type === InteractionType.APPLICATION_COMMAND) {
const { name } = data;

// The command I'm working on
if (name === 'get-video') {
  const userId = req.body.member.user.id;
  const videoPath = "video.mp4";
  const file = new AttachmentBuilder(videoPath);
  return res.send({
    type: InteractionResponseType.CHANNEL_MESSAGE_WITH_SOURCE,
    data: {
      content: `video for <@${userId}> and ${file} and path ${videoPath}`,
      flags: InteractionResponseFlags.EPHEMERAL,
      components: [
        {
          type: MessageComponentTypes.ACTION_ROW,
          components: [
            {
              type: MessageComponentTypes.BUTTON,
              // Append the ID to use later on
              custom_id: `accept_button_${req.body.id}`,
              label: 'my button',
              style: ButtonStyleTypes.PRIMARY,
            },
          ],
        },
      ],
      files: [file]
    },
  });

`
As you can see, I have put the attachment under "files", but nothing shows up! Would sincerely appreciate any help :)