Sends an actionbar message to the player. Use this format:
"actionbar: message;duration" (The duration must be in ticks, 20ticks = 1second)
Title
Sends a title and subtitle message to the player. Use this format:
"title: fadeIn;stay;fadeOut;title;subtitle" (The duration of fadeIn, stay and fadeOut must be in ticks, 20ticks = 1second) If you want just a title, or just subtitle write "none".
Firework
Spawns a firework from the player location. Use this format:
firework: colors:<color1>,<color2> type:<type> fade:<color1>,<color2> power:<power>
The fade property is optional, the rest are necessary. You can add more than 2 colors.