Almost there. Open config.js and paste your AWS values (Cognito domain, app client ID, API URL, and the site URL), then re-upload to S3.
The full step-by-step AWS walkthrough is in README.md.
You'll be taken to a secure AWS sign-in page. Your progress is stored in the cloud, so it follows you across phone and laptop.
Couldn't reach iNaturalist. Check your connection.