What should a person do who intentionally coughed for a long time during prayer, thereby invalidating his prayer out of ignorance of the ruling, and can only recall two of the prayers that were invalidated?

Deliberately coughing during prayer invalidates it if two or more letters are produced from it. However, prayer is not invalidated by coughing, sneezing, or blowing without being overwhelmed. If someone does this out of ignorance, they do not have to repeat the prayer. It is permissible to follow the opinion that there is no obligation to repeat prayers invalidated due to ignorance.