Api calling ionic4

import { HttpClient, HttpHeaders } from '@angular/common/http';

import { Injectable } from '@angular/core';

  import { throwError } from 'rxjs';

import { map, catchError } from 'rxjs/operators';  

constructor(private http: HttpClient) { 

     // development database

    this.API_HOST= "";

    

  } 

  OuterIdBreak(formdata) {    

      const reqHeader = new HttpHeaders();    

      reqHeader.append('Content-Type', 'application/json');

      return this.http.post(`${this.API_HOST}/outbound/outeridbreak/`,formdata)

      .pipe(map(res => res), catchError(this.errorHandler));

    }

 errorHandler(error: Response) {

    console.log("RESULT:::", error);

    return throwError(error);

  }