Impossible to connect while my code has no errurs in ionic

Ionic Framework ionic-v3
1

Hello, I have a small project that I develop on ionic 3 and Angular 5. I create my login page and my service, when I click on the ‘login’ button, I have a validated return on the browser side .
but I can not connect. Your help please

Code : AuthService.ts
02

Code : Login.ts

03
03.png1209×957 84.3 KB

Result in navigator :

01
01.png1397×622 37.1 KB

But I can not connect to the application !