To download service account JSON file go in console.firebase.com then in Project -> Project Settings - > Service Accounts and click on "Generate new private key"
Extract the zip that you got from codecanyon.
Save this file as service-account-file.json in Mobile App/Producer/service-account-file.json
Once again go in your Firebase console.
Then go in Project Setting and create a web app.
In the file structure, locate firebase_config.js.
Copy the values from Firebase to you firebase_config.js.
Step 2. Install the node modules
In Visual Studio terminal run
This may take a while. You may get some errors, but this doesn't necessary means that there are critical errors. Please continue withe the docs. If something is not working, send us screenshot of what you get during this install process.