This issue can be fixed by editing your Mac security settings.
Please use the following steps to disable security settings and open the app anyway.
▼ Method 1
System Preferences > Security and Privacy > General > Allow apps downloaded from:
"VRoidStudio can't be opened because the identity of the developer cannot be confirmed"> "Open Anyway" > Open
▼ Method 2
① In the "Finder ", locate the application you want to open.
* Don’t use Launchpad to do this. Launchpad doesn’t allow you to access the shortcut menu.
② Control-click the app icon, then choose "Open" from the shortcut menu.
③ Click "Open".
The application is saved as an exception to your security settings, and you can open it in the future by double-clicking it just as you can any registered app.
Reference (external site): macOS Sierra: Open an app from an unidentified developer