Error : Argument of type '{ headers: HttpHeaders; responseType: string; }' is not assignable to parameter of type '{ headers?: HttpHeaders | .......

If You have this error in angular request for response type "text",


Argument of type '{ headers: HttpHeaders; responseType: string; }' is not assignable to parameter of type '{ headers?: HttpHeaders | { [header: string]: string | string[]; }; observe?: "bod
y"; params?: Ht...'.

You need to set header from .... 

    let headers = new HttpHeaders({

        'Content-Type': 'application/json',

        'Authorization': window.sessionStorage.token

      });

      let authHttpOptions = {

       headers : headers,

        responseType: 'text'

      }

       this.http.post(url, param, authHttpOptions)

          .subscribe(..)

to 

 this.http.post(url, param, {

          headers: new HttpHeaders({'Content-Type': 'application/json', 'Authorization': window.sessionStorage.token}),

          responseType : 'text'

 })

          .subscribe( ...)