Your code literally output the line
url: mongodb+srv://MONGO_URL_NAME:MONGO_PASSWORD@MONGO_URL_CLUSTER/...
This means one of 3 things:
1 - your .env is not configured correctly
2 - your .env is not processed correctly, the lines that starts with dotenv-flow: might give some clues
OR
3 - your code does not use the content of your .env correctly
You will need to share your .env and the code that uses your .env.
But first read Formatting code and log snippets in posts.