You can’t convert Roblox VNG into the global Roblox app inside the app; you need to uninstall Roblox VNG and install the standard Roblox version instead.

Simple steps

  1. Uninstall Roblox VNG from your device.
  1. Open your app store and make sure your store region/account is not set to Vietnam, because that can keep showing the VNG version.
  1. Search for Roblox and install the official app published by Roblox Corporation.
  1. Log in with your existing Roblox account after installation.

Important note

If your account or region is tied to Vietnam, Roblox VNG may be the only version offered there, and some account-location settings may be fixed or require support review.

Safety tip

Avoid random APK downloads or unofficial sites, since those can be unsafe or modified.

Answer in one line

Remove Roblox VNG, change to a non-Vietnam store region if needed, then install the official global Roblox app.

TL;DR: Roblox VNG is a separate regional version, so the fix is uninstall + reinstall the global app, not a setting change inside Roblox.