You should add this entry to every slot machine entry in your config (see example config for more info)

    messaging:
      message: '$6$[MCCasino] $7$$name$ won $$amount$!'
      send_to: players_nearby
      exclude_winner: true
      radius: 20

Values for the "send_to" field are : PLAYER, PLAYERS_NEARBY, WORLD, SERVER, CONSOLE_ONLY
Those aren't case sensitive. To disable the message sender, use "CONSOLE_ONLY".

if you want to those values to your config, add this at the end

    # PLAYER, PLAYERS_NEARBY, WORLD, SERVER, CONSOLE_ONLY

The radius value is only used when PLAYERS_NEARBY is chosen. Any player within this radius (originating from the player using the slot machine) will receive this message.

If you need the color codes, you can add this to the end of your config

    # Black: $0$
    # Dark blue: $1$
    # Dark green: $2$
    # Dark aqua: $3$
    # Dark red: $4$
    # Dark purple: $5$
    # Gold: $6$
    # Gray: $7$
    # Dark gray: $8$
    # Blue: $9$
    # Green: $a$
    # Aqua: $b$
    # Red: $c$
    # Light purple: $d$
    # Yellow: $e$
    # White: $f$
    # $name$ = player's name
    # $amount$ = amount of items/money won
    # $item$ = name of item won