Create First Activator

The best way to learn how to use ReActions is creating your first simple activator.

Here is step-by-step instruction of activator that will teleport you in predefined location when after pressing a button.

Actions	Comment
Place button on the block. Point your cursor on this button and type command: /react add button tpbut	Creating a new button-activator. Word button is an activator type. You can create another activator of other type. For example: /react add region_enter regionact will create new REGION_ENTER activator named "regionact"
Now you must move to target location and type command /react add tpbut action TP %here%	Creating a teleport (TP) action linked to activator tpbut. %here% is a placeholder that will be replaced with player location.
Move back to your button and press it.	Congratulations! Your first activator successfully created!

Configure activators directly in activator file

This activator will be saved in activator.yml file. And you can edit this file manually:

BUTTON:
  tpbut:
    world: world
    x: 1355
    y: 80
    z: -2122
    flags: []
    actions:
    - TP=world,1355.389,84.0,-2113.658,180.884,36.6
    reactions: []

Video tutorial

You can find more ReActions tutorials in this playlist.