let apiUrl = "./assets/test.bin";
const headers = {
  headers: new HttpHeaders({responseType: "application/octet-stream"})
};

let data : Observable<Uint8Array> = this.http.get<Uint8Array>(apiUrl, headers);
data.subscribe( (response: Uint8Array) => {
  const data = response;
  // console.log(data);
  console.log("successful");

  return data;
}, (error : HttpErrorResponse)=> {
  console.log(error.error.text);
});

let apiUrl = "./assets/test.bin";
const headers = {responseType: "blob"};

let data : Observable<Blob> = this.http.get<Blob>(apiUrl, headers);
data.subscribe( (response: Blob) => {
  const data = response;
  console.log(data);
}, (error : HttpErrorResponse)=> {
  console.log(error.error.text);
});