Might be a bit late to reply, but the URL you are using is no longer part of the free plan and that's why you get that error. Try using the following URL, it requires the user to input a city name and there is no need of using latitude and longitude.

https://api.openweathermap.org/data/2.5/weather?q=${*cityName*}&appid=${*API_key*}&units=metric

So, if you have a text field that takes the input for a city name, then the above fetch call would work.

Here cityName is the location entered by the user and API_key is the API key you are assigned. By having &units=metric, you will get the temperature in degree Celcius. If you want the temperature in Farenheit, use &units=imperial or if you want the temperature in Kelvin, just get rid of the &units=metric part.

So for example if you paste the following in your browser, you will get the weather in London.

api.openweathermap.org/data/2.5/weather?q=London&APPID=YOUR_API_KEY

Hope my first answer on this platform helps somebody.