How to use [io.file.load]

The reference page of io.file.load has its arguments, constraints and declaration.

Loads the specified text file from disc. This slot can only load text files. Or to be specific, there are no ways you can change binary files, hence loading a binary file is for the most parts not something you should do. Although there might exist exceptions to this.

io.file.load:/misc/README.md

Notice - If you want to load binary content you should use the [io.file.load.binary] override.