Urgent API Debugging for Weather Website

My website is failing to pull data from an external API and I need this fixed urgently. The site was working fine last week but suddenly stopped displaying the data. I'm getting errors but I'm not technical enough to understand what's wrong.
The Problem:
My website pulls weather data from a third-party weather API to display current conditions on the homepage. Since yesterday, the weather widget shows "Error loading data" instead of the actual weather information.
What I Need:
- Check API keys and verify they're still valid
- Review API endpoints to make sure they're correct
- Debug the request handling code
- Identify and fix the connection error
- Test to confirm data is loading properly
Technical Context:
- Website built with JavaScript
- Using fetch requests to call the weather API
- API documentation says I'm using v2 but they may have updated
- Error appears in browser console but I don't understand it
- No recent code changes on my end
This should be a quick debugging task for someone experienced with API integrations. I just need it working again.