Let us use the magical powers of a "search bar" to answer our questions! If you search, you will find a variety of plugins that do this. ButtonCmds, TriggerCmds, DynaButton, ButtonWarp, etc.
np98765 is right xD there are so many plugins that does this xD Honestly I tried button commands and it was kinda buggy xD Because ppl could bug the mob arena and keep the items lol anyways Use trigger cmds xD its a little trouble to set up all the buttons but its worth it