import { BaseEsmsService } from './base.service';
import type { SmsSendResponse } from '../types';
/**
 * Viber Service - handles Viber OTT operations
 */
export declare class ViberService extends BaseEsmsService {
    private readonly endpoints;
    /**
     * Send Viber OTT message
        * @param credentials Optional credentials, will use default from constructor if not provided
     */
    sendViber(request: {
        Brandname: string;
        Content: string;
        Phones: string[];
        OttImgUrl?: string;
        OttLabel?: string;
        OttUrl?: string;
        SmsType?: '23';
    }, credentials?: {
        apiKey: string;
        secretKey: string;
    }): Promise<SmsSendResponse>;
}