import { HttpEvent, HttpHandlerFn, HttpRequest } from '@angular/common/http';
import { Observable } from 'rxjs';
/**
 * An HTTP interceptor to append an Authorization header with a Bearer token
 * to outgoing HTTP requests if certain conditions are met.
 *
 * @param {HttpRequest<unknown>} req - The outgoing HTTP request object which may be modified.
 * @param {HttpHandlerFn} next - The next handler in the HTTP request pipeline.
 * @return {Observable<HttpEvent<unknown>>} An observable of the HTTP event stream resulting from the request.
 */
export declare function apiTokenInterceptor(req: HttpRequest<unknown>, next: HttpHandlerFn): Observable<HttpEvent<unknown>>;