What follows is the OCaml library documentation when you pull in the Opam module dkml-install using something similar to the following in your *.opam file:
Typically you get dkml-install.api automatically when you pull in dkml-install.register. If you need the API library by itself, in your Dune file dune you can include the library as follows:
(library
(libraries dkml-install.api))
The entry point of this library is the module: Dkml_install_api.