When Apple updated iOS devices to iOS 13 they removed the loupe feature that allowed you to navigate text more accurately. If you’re looking to position your cursor precisely in text there are two options.
One, is to hold your finger over the text. This works but has the annoying side effect of accidentally selecting a word.
The better approach is to long hold the spacebar. This will briefly pulse the cursor and then you can use the screen as a trackpad to move the cursor to precisely where you need it.