/**
 * Utility for creating iframe URLs with tokens in the hash.
 *
 * The token is placed in the URL hash as `mb_token=<encoded_token>` so that
 * the iframe content can retrieve it using the getToken() utility.
 */
/**
 * Creates an iframe src URL with an optional token in the hash.
 *
 * @param url - The base URL for the iframe
 * @param token - Optional authentication token to include in the hash
 * @returns The URL with the token appended as a hash parameter if provided
 *
 * @example
 * getIframeSrc('https://example.com', 'my-token')
 * // Returns: 'https://example.com#mb_token=my-token'
 *
 * @example
 * getIframeSrc('https://example.com', undefined)
 * // Returns: 'https://example.com'
 */
export declare function getIframeSrc(url: string, token: string | undefined): string;