get undefined when requiring data from another file which queries mongodb collection

Question

in the export.js file, everything works fine, I can consoleLog the correct collection queried from mongodb, but in the import.js file, the collection is consoleLogged immediately and is undefined, I don't know what's wrong

 //export.js
module.exports = client.connect(async () => {
      const db = client.db("database");
      const collection = await db.collection("collection").find().toArray();
      client.close();
      console.log(collection);
      return collection;
    });

//require.js
const collection = require("./export");
console.log(collection);