If you don't know how to do a big jump just put a thing that has a tag and put it above the player does not matter how high and when the jump button Is pressed it says to the player (if player colliding with ground move towards ( up) an speed 3) and here you have it

And ad to the player axis lock so he does not rotate

If you don't want that people fly just put every block a tag like ground . Than when the jump button is pressed it a tells the player (if player is colliding with ground jump else do nothing ) and do the jump a little hiher

Look I can help you

I am in creative

Put into the player the code ( when this collides with actor #ground reset a variable $jump_strength )