The compiled data is written to a .rbxl (Roblox Level) or .rbxlx (XML format) file, typically dropped into the "workspace" folder of the execution tool. The Difference Between Map Saving and Full Decompiling
saveinstance() is a custom Luau function injected by third-party Roblox executors (such as Synapse Z, Wave, Wave Android, or Solara). It does not exist within the official Roblox API documentation because Roblox explicitly blocks normal game clients from downloading place files directly from a server. Roblox SaveInstance Script
Roblox Terms of Service explicitly forbid: The compiled data is written to a
If you are using a standard external executor, the syntax is usually a single line: Roblox SaveInstance Script