You might try:

BullModule.forRoot({
    redis: {
        host: "YOUR_REDIS_HOST",
        port: 6379,
        db: 0,
        password: "YOUR_REDIS_PASSWORD",
        tls: { // Specifiy the host and port credentials again here
            host: "YOUR_REDIS_HOST",
            port: 6379,
        }
    }
})