@Neongho Do you mean render text in a material, or a freeform ability to paint decal shapes on the world geometry during runtime?
To “paint” onto a material at runtime, you can use ScriptedTexture and use something like DrawBlendedTile() to paint onto the material at specific co-ordinates.
I use this approach to paint a fog-of-war opacity mask on a shroud material for my in-game map, which you can see in video: https://youtu.be/Z_OWNkiorQI