Connection error at EXPO

Question

Some of you, like me, must have done last Omnistack Week.

I am having an error when connecting my back-end Login route in my front-end. I am using the axios for that. When I give a yarn start or expo startthe Expo interface is open and I connect with the application on my mobile. The login screen appears normally, the problem happens when I press the login button.

Error:

[Unhandled promise rejection: Error: Network Error]

Stack trace:
  node_modules\axios\lib\core\createError.js:16:24 in createError
  node_modules\axios\lib\adapters\xhr.js:81:25 in handleError
  node_modules\event-target-shim\lib\event-target.js:172:43 in dispatchEvent
  node_modules\react-native\Libraries\Network\XMLHttpRequest.js:580:29 in setReadyState
  node_modules\react-native\Libraries\Network\XMLHttpRequest.js:394:25 in __didCompleteResponse
  node_modules\react-native\Libraries\vendor\emitter\EventEmitter.js:190:12 in emit
  node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:366:47 in __callFunction
  node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:106:26 in <unknown>
  node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:314:10 in __guard
  node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:105:17 in callFunctionReturnFlushedQueue

I did the route tests with Insomnia and they are working properly, someone can help?