Question: I am creating an API with our API server script and am trying to communicate with the API on the IONIC framework application. I am working but it keeps on bringing up the cross-origin blocked error: 

[![enter image description here](https://i.stack.imgur.com/x1jg4.png)](https://i.stack.imgur.com/x1jg4.png)

Answer: 
If you have no way to change the server configuration, you should use [Http native plugin](https://ionicframework.com/docs/native/http/) to perform Http requests from your mobile device, to prevent cors problems. However, in web enviroment you still need to use Angular's HtttClient. Fortunately, with [ionic-native-http-connection-backend](https://github.com/sneas/ionic-native-http-connection-backend) library you can use the same HttpClient service for both enviroments, and Http native will be used internally if the app is executed from a mobile device. It's a kind of wrapper.
Cors error can only be resolved from server side.
But yes for browser only we can resolved it by installing cors extension but for device can be only from server side