what is the namespace for textmesh pro

C#
using TMPro; //This namespace allows you to use TMP related actions

public GameObject GameObject //Second word is variable type
//Make sure you make a ref. in inspector   //You can name the 3rd word whatever
  
GameObject.GetComponent<TextMeshProUGUI>().text = "Whatever";
  				//above is the special TMPro name space
Source

Also in C#: