As it is a Swyama Siddha Hanuman Mantra it doesn't have to be chanted for a fixed quantity of Mantra Repetitions for having the ability to use it. Particular worship and rituals and guidelines pertaining to direction, sitting mat, and counting rosary are certainly not proposed for chanting this Hanuman https://www.youtube.com/watch?v=ufkmD95y7fE&t=32s