Here's a Jump Refresher code I used
if image_alpha = 1 {
if instance_exists(player){
player.djump = 1;
}
image_alpha = 0;
instance_create(x, y, JumpBonusText);
alarm[0] = 150;
}
//this means when player touch it, you can get player's djump to 1.
use this to when the jump refresher object collides to player, and if you need it for player2(reversed gravity) use that, and change 'player' to 'player2'
image_alpha = 1;
use this at alarm 0. This is for jump refresher's alpha being 1, which is for jump refresher being restored.
Sorry I couldn't make it simpler