Basically, the Alif of the article should have "hamza + fatha", the Lām does not take a vowel marker, because it is assimilated to the following consonant which is one of the "Sun consonants" (حروف شمسية i.e. ت ث د ذ ر ز س ش ص ض ط ظ ل ن ). The Sun consonants always provoke this assimilation of the article. This is also why you have the tashdīd (تشدید) on the Sun consonant (because now it is pronounced doubled=long). So the word reads (with full i'rāb): az-zauĝu

like Denda said it's called "LAM SHAMCIA" so we don't vocalize it, you can read it (AZ-ZAWG)

not az-zawg?

this "ل" is called " Lam Shamsiya" which is only written and never spelt so u could pronounce it as "Azawg"