JSR citation style

I am contacting EndNote on behalf of the Journal of Sleep Research, who would like to see their house style to be delivered automatically in EndNote software rather than have to be downloaded manually. Please let me know how to take this forward or who I should be addressing with this request.

I would suggest that you go here (we can’t help you – we are a user based forum), but it sounds like you already have an output style?  There is no way that Endnote can or should include every specialist output style.  I for one, would have no need for your style, and the more styles, downloaded with Endnote, the slower the software becomes.  6000+ styles would be crazy.