Chapter 1: The Book of Purification
It was narrated that Anas bin Malik said: "The Messenger of Allah (ﷺ) entered Al-Khala' (the toilet) and said: 'Allahumma inni a' uthu bika min al-khubuthi wal-khaba' ith (O Allah, I seek refuge with You from male and female devils)."[1]
[1] See Ma' alam As-Sunan by Al-Khattabi. And Al-Khala' is the area one relieves oneself in. It refers to outside or other than that, it should not be understood to mean toilet only.
Sunan an-Nasa'i 19