I need to subscribe to topic in login function, I get the device token and push it into array named tokens

And I use fcm function to subscribe, First : import fcm and intialize a new fcm with my server_key :

var FCM = require("fcm-node");
let fcm = new FCM(process.env.SERVER_KEY);

Then use this function to subscribe to topic

const tokens = [];

// deviceToken it contain my device Token
tokens.push(deviceToken);

fcm.subscribeToTopic({ deviceToken: tokens }, { topicName: "general" })
   .then((resposne) => {console.log(resposne)})
   .catch((error) => {console.log(error)})

It return in terminal:

 CB(err, res);
                ^

TypeError: CB is not a function

and i try to change the function to :

fcm.subscribeToTopic(deviceToken, "cars", (err, response) => {
    if (err) {
      console.log("subscribeToTopicError:", err);
    } else {
      console.log("subscribeToTopicResponse:", response);
    }
  });

it return { statusCode: 400, message: 'Bad Request' }

How can i subscribe to topic with nodejs ?