How to Connect MongoDB to Payload CMS

I am new to MongoDB. I am trying to setup Payload CMS backend and I am getting this error…

Any information would be great! For context, I want to create a basic website with Nextjs Frontend and Payload CMS backend. Thanks!

This reads like the mongo connection value isn’t being passed in. Most examples have this set from an environment variable. Is this value set in an .env file? If you’re missing that file, you may need to copy an .env.example if that’s available.