The plugin supports various different PlaceholderAPIs built in to the plugin! You do not need to install anything else to use these, just the plugin.
Each skill has the following placeholders. Replace <skillname> with the lowercase name of the skill (e.g., mining, fishing).
The 19 skills are: acrobatics, alchemy, archery, axes, crossbows, excavation, fishing, herbalism, maces, mining, repair, salvage, smelting, spears, swords, taming, tridents, unarmed, woodcutting
%mcmmo_level_<skillname>%%mcmmo_xp_needed_<skillname>%%mcmmo_xp_<skillname>%%mcmmo_xp_remaining_<skillname>%%mcmmo_rank_<skillname>%%mcmmo_xprate_<skillname>%As for everything else:
%mcmmo_power_level%%mcmmo_power_level_cap%%mcmmo_in_party%%mcmmo_party_name%%mcmmo_is_party_leader%%mcmmo_party_leader%%mcmmo_party_size%%mcmmo_is_xp_event_active%%mcmmo_xprate%