Custom certificate (plugin)

You can place you links to pdf files of certificates?

That looks like it needs a context, the path to the pdf is constructed with the context, Course module ID '$id' parameter is passed to get the context but how to get this ID?

$ context = get_context_instance (CONTEXT_MODULE, $ cm-> id);

I see the path according to the pdf is like this: $ CFG-> wwwroot. '/ pluginfile.php', '/'. $ context. '/ mod_certificate / issue /'. $ certrecord-> id. '/'. $ filename );

Anyone know how I could get the context?

Thanks and Regards
Jorman