I know I can do it like this: PlaceholderAPI.setPlaceholders(.., ...). But how do I get my placeholder to work in other plugins?
You have to create and register your own placeholders. This tutorial isn't up to date, but it should works. You must only replace: Code (Java): @Override public String onPlaceholderRequest(Player p, String identifier) with: Code (Java): @Override public String onPlaceholderRequest(OfflinePlayer p, String identifier) {