As that is a Swyama Siddha Hanuman Mantra it does not have for being chanted for a fixed number of Mantra Repetitions for being able to utilize it. Distinctive worship and rituals and principles relating to direction, sitting down mat, and counting rosary are certainly not advisable for chanting this https://www.youtube.com/watch?v=ufkmD95y7fE&t=32s