Error: Invalid scheme, expected connection string to start with "mongodb://" or "mongodb+srv://"

Hello,

I am very new to this. I first for the error of

Error: The uri parameter to openUri() must be a string, got “undefined”. Make sure the first parameter to mongoose.connect() or mongoose.createConnection() is a string.

but my conectDB was below dotenv. I saw someone saying ‘process.env.MONGO_URI’ should be in string so i did that, while the error disappeared, this new error is now here.

I have searched for some solutions but nothing seems to work.

MONGO_URI = 'mongodb+srv://user:password@cluster0.cdusxnp.mongodb.net/?retryWrites=true&w=majority'

const mongoose = require("mongoose");
const colors = require("colors");

const connectDB = async () => {
  try {
    const conn = await mongoose.connect("process.env.MONGO_URI", {
      useNewUrlParser: true,
      useUnifiedTopology: true,
      useFindAndModify: true,
    });

    console.log(`MongoDB Connected: ${conn.connection.host}`.cyan.underline);
  } catch (error) {
    console.log(`Error: ${error.message}`.red.bold);
    process.exit();
  }
};

module.exports = connectDB;

Any help would be appreciated, as my presentation is tomorrow ^^