UEStudio is an IDE - Integrated Development Environment, but is installed without any compiler, script interpreter or debugger. You have to download, compile or install LUA script interpreter by yourself and integrate it also by yourself. You can run the LUA interpreter either as user or project tool - see
Advanced - Tool Configuration respectively
Project Tool Configuration and the help page for tool configuration dialog, or you take the time and write a config file for using LUA interpreter from within UEStudio using the "Compile", "Build" and "Rebuild" commands, although those commands are normally used only for programming languages where the source files must be compiled and not just interpreted as LUA or JavaScript scripts.
The options you have when writing a config file are described in help of UEStudio on the pages starting with square bracket
[ in title which are listed all at top of the
Index tab of the UEStudio help.
It is surely not possible to debug LUA scripts directly from within UEStudio because integrated debugging support is available only for the debuggers WinDbg (Microsoft C/C++) and Xdebug (PHP). UEStudio supports only calling an external debugger from within UEStudio for other languages respectively compilers and script interpreters.
So you need to read a lot of documentation on
www.lua.org to more integrate LUA interpreter and debugger into UEStudio, or you wait that somebody else posts here how to do this. But I would not wait too long time for help by another user of UEStudio or UltraEdit also programming LUA.