FusionReactor will automatically attempt to use the CFML source code running in your ColdFusion server when using either the decompiler or the debugger, however, this is not always possible.
It is possible to view your CFML code as opposed to the decompiled Java code by configuring a debug source, you can do this by navigating to Debug > Debugger in FusionReactor and adding a source of the directory for your source code.
You can find more information on configuring your sources at https://docs.fusion-reactor.com/Debugger/Sources/.