Uload file on custom module via rest api 4.1

I’ve created a custom module of document type.
I need to upload a file in cusrom module using web service (standard REST api 4.1) but I can’t find the right parameter to use.
I can create the record, but the file was not uploaded.

Here the JSON parameter I’m using:

“document_name”:“Sample Image”,

Is it possible upload a file in custom module?
Which the right name/parameter to use to do that?