How do I return the value within a . then in Vue JS?

Question

I’m new to Vue and Firebase, I have the following problem: I want to return the generated value inside then, in the console.log that is inside then returns the id that was generated, but when I refer the same id outside then I get a Undefined.

  enviarDados(){
    db.collection('teste').add(this.user)
    
    .then((docRef) => {
        this.idGerado = docRef.id
        console.log('Meu id:', this.idGerado)
    })
    .catch((error) => {
        console.error("Error adding document: ", error);
    }); 

    console.log(this.idGerado)

  }