1. Im trying to follow this video https://www.youtube.com/watch?v=4AUuhhSakro for making 2 dependent dropdown buttons, the thing is where he makes the API call on on Future String _function() async {} it asks me to return or throw something at the end and gives me an error, and in his video it does not require a return or gives him an error.

  2. Also it throws an Error: XMLHttpRequest error. I have configured CORS on my Rest Api in node js. When I do a simple get and show it on console it totally works. But when doing it in here, in my dropdown, it throws that error, I see he has a header and a body where he calls an api_key, where in postman can I find the header and the api_key?