How to get image url from Aws s3 and store it in mongodb using lambda function in nodejs

Question

I need a URL location of an image from AWS s3 and store it in MongoDB with the lambda function. I know how to do this simple way using servers, attached code is working great, uploading the image and then getting the image url from the bucket and saving into mongodb. but I want to do this same using lambda function. Please help me to code this in lambda function and guide me step by step ,I am totally new to this aws lambda

userController.js :

const aws = require("aws-sdk");
const multer = require("multer");
const multerS3 = require("multer-s3");

const User = require("../models/userModel");

const s3 = new aws.S3({
  accessKeyId: process.env.S3_ACCESS_KEY,
  secretAccessKey: process.env.S3_SECRET_ACCESS_KEY,
  region: process.env.S3_BUCKET_REGION,
});

const upload = (bucketName) =>
  multer({
    storage: multerS3({
      s3,
      bucket: bucketName,
      metadata: function (req, file, cb) {
        cb(null, { fieldName: file.fieldname });
      },
      key: function (req, file, cb) {
        cb(null, `image-${Date.now()}.jpeg`);
      },
    }),
  });

exports.setProfilePic = (req, res, next) => {
  const uploadSingle = upload("profile-picture-upload-youtube").single(
    "croppedImage"
  );

  uploadSingle(req, res, async (err) => {
    if (err)
      return res.status(400).json({ success: false, message: err.message });

    await User.create({ photoUrl: req.file.location });

    res.status(200).json({ data: req.file.location });
  });
};

`