You just place your finger on where you generally want it to go, and hold it there for a moment until a “magnifying glass” pops up that allows you to drag and place it precisely.
edit:
just want to add that I don’t think I ever read this anywhere. I discovered it while mildly enraged, when I poked and held the screen while saying “FUCK YOUUUUUUUUUUU” and then the magnifying thing appeared and I was like “oh”