By default, in H5P, if you disable the ‘Embed’ button as part of the toolbar for your H5P Content, then you completely disable the ability to embed that piece of content anywhere – even you as the author of the content.
There is a H5P_EMBED_URL_ALWAYS_AVAILABLE constant available within the H5P WordPress plugin which, when set, allows disabling the embed button, whilst still being able to embed the H5P content elsewhere.