Firebase javascript v9 getMessaging().subscribeToTopic() undefined

I am using firebase javascript api v9 in my react project and i am using the code below as suggested by the oficial documentation

    import { getMessaging } from "firebase/messaging";
    
    // These registration tokens come from the client FCM SDKs.
    const registrationTokens = [
      'fcm_token_string'
    ];
    
    // Subscribe the devices corresponding to the registration tokens to the topic
    getMessaging().subscribeToTopic(registrationTokens, topic)
      .then((response) => {
        // See the MessagingTopicManagementResponse reference documentation [enter link description here][1]for the contents of response.
        console.log('Successfully subscribed to topic:', response);
      })
      .catch((error) => {
        console.log('Error subscribing to topic:', error);
      });

However, despite of doing exactly what the documation of firebase api v9 says, I am getting undefined when accessing getMessaging().subscribeToTopic function.

I am wondering if this function was moved to another component and the documentation has become outdated.

I would appreciate any help. Thank you in advance.