Can't resolve all parameters for UserServiceService: (?)

Question

I'm trying to get users data by the link given in getsUserUrl.To do that it requires a token(see the token variable) that I have added in the header. .Whenever I start the server I get an error like this.

Can't resolve all parameters for UserServiceService: (?).at syntaxError (compiler.js:1021)

Here is my code. I don't know what parameter am I missing in Header.

import { Injectable,Pipe } from '@angular/core';
import { HttpHeaders, HttpClient ,HttpErrorResponse,HttpClientModule} 
from "@angular/common/http";
import { catchError } from 'rxjs/operators';
import { throwError } from 'rxjs';
import 'rxjs/add/operator/map';
import { Token } from '@angular/compiler';

 @Injectable({
 providedIn: 'root'
  })
  export class UserServiceService {

  usersData: any[] = [];
  user:string

  getUserUrl="https://auth.openshift.io/api/search/users?q=rohit";
   token=`eysdsfdp.whsofd23.fdiu`;
   constructor(private httpclient:HttpClient) {
    }
     private handleError(err: HttpErrorResponse | any) {
    console.error('An error occurred', err);
     return throwError(err.message || err);
    }
 searchUsers()
 {
    const httpOptions = {
     headers: new HttpHeaders({
    'Content-Type':  'application/json',
    'Authorization': `Bearer ${this.token}`
    })
  }; 
     var res=this.httpclient.get(this.getUserUrl,httpOptions);
    return res.pipe(catchError(this.handleError));
}

 }

Please let me know what am I doing wrong. I'm attaching the code photo for your reference

As the person wanted my component code, I'm adding that too here

Answer 1

You need to place authorization keyword in quotes as well

const httpOptions = new HttpHeaders({
'Content-Type':  'application/json',
'Authorization': `Bearer ${this.token}`
});

Or you can define it this way also

let httpOptions = new HttpHeaders();
httpOptions = httpOptions .set('h1', 'v1').set('h2','v2');