onRequest method
Called when the request is about to be sent.
Implementation
@override
void onRequest(
RequestOptions options, RequestInterceptorHandler handler) async {
String appAccessToken = await authService.getCurrentAppAccessToken();
options.headers.remove(HttpHeaders.authorizationHeader);
options.headers[HttpHeaders.authorizationHeader] =
'Bearer ' + appAccessToken;
handler.next(options);
}