[update]

src/app/core/service/auth/cathay-auth.service.ts

@@ -0,0 +1,22 @@
+import { HttpClient } from '@angular/common/http';
+import { Injectable } from '@angular/core';
+import { BaseService } from 'src/app/core/base/base-service';
+import { environment } from 'src/environments/environment';
+
+@Injectable({
+  providedIn: 'root'
+})
+export class CathayAuthService extends BaseService{
+    API_URL = environment.CATHAYAPIURL
+    constructor(
+        public http: HttpClient
+    ) {
+        super('', http)
+        super.fullUrl = `${this.API_URL}/v1/User`
+    }
+
+    login(payload : {'mobileDeviceId': string , 'userName': string , 'password' : string}){
+        return this.http.post(`${this.fullUrl}/login`, payload)
+    }
+
+}