export declare class SigningRoomElement extends HTMLElement {
    private iframe;
    private targetOrigin;
    private messageListener?;
    private _isReady;
    private _queuedPsbt;
    constructor();
    connectedCallback(): void;
    loadPsbt(psbtBase64: string): void;
    disconnectedCallback(): void;
    handleMessage(event: MessageEvent): void;
}