This word ‘dua’ could be roughly translated to mean supplication or invocation. It is conversatin between you and Allah(subhana wa ta'ala) our Creator, our Lord, the All Knowing, and the All Powerful.
we can ask Allah(subhana wa ta'ala) what ever we want except that is doesn't given permission in islam
"Once Rasulullah (solellahu alihi wasallam)
Allahumma innee Asaluka fealal-kirati watarkal munkarrati wahubbal masaakene wa antagfirlee watarhamnee wa ezaa aradtan fitnatan fee qawme fatuwaffe ni gira maftoonin
OAllah! I ask of You the ability to do good, to shun evil, to love the poor and that You forgive me, have mercy on me and when You intend to put any nation to test, grant me death without testing me.