How to update other players after adding a character to the text UI

Question

Hello I'm new to multiplayer development and I'm using photon pun 2 in Unity engine C# language. How can I update other players every-time I add another character to my text UI. The characters that was added on the text only appears on my screen only and sometimes just on the screen of another player.

This is my current code for that function. How can I make the text appear on all the players screen.

public Text _letterToShow;
string letter;

 private void OnTriggerEnter2D(Collider2D other)
{
    if (other.gameObject.CompareTag("Player"))
    {
        letter = other.gameObject.transform.GetChild(2).name;
        _letterToShow.text += letter;
    }
}

I have already added PhotonView to the _letterToshow Text UI Object. Your Help would be really much appreciated. Thank you