As that is a Swyama Siddha Hanuman Mantra it doesn't have to be chanted for a fixed quantity of Mantra Repetitions for being able to use it. Particular worship and rituals and policies about direction, sitting mat, and counting rosary usually are not suggested for chanting this Hanuman Mantra. The https://www.youtube.com/watch?v=ufkmD95y7fE&t=32s