As it is a Swyama Siddha Hanuman Mantra it doesn't have to be chanted for a fixed amount of Mantra Repetitions for having the ability to utilize it. Distinctive worship and rituals and principles pertaining to way, sitting mat, and counting rosary usually are not recommended for chanting this Hanuman https://www.youtube.com/watch?v=ufkmD95y7fE&t=32s