import { OnModuleInit } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
export declare class FirebaseService implements OnModuleInit {
    private readonly configService;
    private readonly logger;
    private firebaseApp;
    constructor(configService: ConfigService);
    onModuleInit(): void;
    sendPushNotification(tokens: string[], title: string, body: string, data?: any): Promise<void>;
}