How do you draw from tilepallet to tilemap while the game is running?

I would like to learn how to at launch pick a tile at startup like lets say tile number two on a 16x16 tile pallet and draw it at a specific spot such as the 5th tile in on the tilemap so that it is visible.

I believe it is supposed to use somet$$anonymous$$ng like SetTile(Vector3Int position, Tilemaps.TileBase tile);

I am unsure how to use that for example with "position" how do I put in the xyz coordinates and do I use specific or just the number of tiles over?

my tile map is named Tilemap I am using 16x16 sprites on tilemap that is 64x48 tiles. I can, of course, draw onto it in the unity editor but I don't know how to update or change the tiles w$$anonymous$$le the game is running.

Thank You