Should the adhkar be recited silently or aloud? May Allah reward you with abundant good.

The default is to perform all dhikr (remembrance of Allah) silently, for which no command of vocalization has been established, in order to avoid showing off and conceit. However, if there is a benefit that necessitates vocalizing it, such as awakening the heedless, or warding off drowsiness and laziness, or encouraging and assisting others, then in these cases, vocalization is preferable.