What is actual ism e azam? How I can get ism e azam

Only I know that is means "the Word of Allah"

But the whole quran is kalaam of Allah (S. W. T)

But there are only 73 ism e azam that’s why i am asking you what is actually ism e azam is?

You are right, all the names of Allah are consider as isme azam. 73 also the Names of Allah. There is no particular name to be consider as Isme Azam. Recite duas with sincerity and practice and duas narrated by ahlolbait a.s