In short, It cannot make calls or send messages to modern Zalo users. At best, it will crash. At worst, it will silently steal your data while displaying a fake "Connecting..." screen.
: Some mods claim to offer deeper control over "seen" receipts or "typing" indicators. Zalo 1.0.44 Mod.apk-
: Changing themes, fonts, and layouts beyond the standard UI/UX provided by VNG. In short, It cannot make calls or send
Which of those would you like?
If you want the benefits of a modded Zalo (privacy, no ads, lightweight feel) without the risk, consider these legitimate options: it will crash. At worst