You don’t need to be afraid of finding typos. For the most part when someone finds a typo, at worst, it will distract them. A very, very, very minor frustration. For an examiner it is something to record in some way, so that they can ask the candidate to make appropriate changes later.
If you find a typo you can do the same.
Typos don’t need to be feared, they need to be found! When you encounter them, note them down, what is needed in the future to make them right and move on.
There’s far more important work to do and far more important things to talk about in the viva.