How to add block to show download option

Description of issue or problem I’m having:
how to add the block to download an published monograph in OMP omp-3.3.0-6

Steps I took leading up to the issue:

What I tried to resolve the issue:
i read the documentation, trying to look up for an plugin that enable it

Application Version - e.g., OJS 3.1.2:

Additional information, such as screenshots and error log messages if applicable:
issue like this with block
issue like this

You can add book formats and files here.
Publication > Publication Formats > Add publication format

Note: If you have published the monograph, you must first unpublish it.