Bismillah,
Du'a is a very powerful tool whereby a servant implores and supplicates to Allah swt who is our Master.
In order to increase one's life span it has been narrated by the pristine household of the Ahlulbayt a.s. to give charity to the poorpoor and those who are living in impoverished conditions. This noble act and kind gesture is highly recommendrecommended in Islam apart from reciting some particupar Du'as as prescribed by the blessed prophet saw.