I got an error cod: 404 Not found city when I tried to use the API that FCC recommenned use in https://openweathermap.org/current#geo
Did you register? Because you need to, in order to get an API key.
PS. There is nothing stopping you using another API.
Take my suggestion and don’t use OpenWeatherMap. I would suggest skipping this project for now anyway, it can be very frustrating and will soon be only an optional addition to the FCC curriculum.