Set a TextMeshPro text value with Unicode characters and add a new line character.
//get object
var my_text = GameObject.Find("My TMP Text").GetComponent<TMPro.TextMeshProUGUI>();
//add 10 spaces at the end of the line
//doesn't show up in the ui
my_text.text = "something ";
//add 1 spaces at the end of the line
//DOES show up in the ui
my_text.text = "something\u00A0";
//add 10 spaces at the end of the line
//DOES show up in the ui
my_text.text = "something\u00A0\u00A0\u00A0\u00A0\u00A0\u00A0\u00A0\u00A0\u00A0\u00A0\u00A0";