How do you kill a player standing on a specific block?

Question

I'm making a Parkour Map and I need to know how to execute /execute @a ~ ~ ~ detect ~ ~-1 ~ minecraft:grass 0 /kill @p[c=1] in 1.13.
It doesn't work for me, because this code was used in version 1.9 or thereabouts. I'm playing on PC.

How do you do execute this command in 1.13?

Answer 1

execute as @a at @s if block ~ ~-1 ~ minecraft:grass run kill @s

This selects all players, individually checks each player to see if the block beneath them is grass, then kills off the player if it is.

A good place to look up what you can do with the execute command is on the Minecraft Wiki