How do you get 3 hearts in Minecraft?

I wanted to ask what command I have to do so that I have only 3 hearts in the Minecraft 1.13.2 so that I can try this challenge.

Replaceitem entity @a armor.head minecraft: stone_button {AttributeModifiers: [{Operation: 0, UUIDLeast: 3, UUIDMost: 3, Amount: -14, AttributeName: generic.maxHealth, Name: head}], HideFlags: 63, Enchantments: [{id: binding_curse, lvl: 1}]}

You can't wear a helmet anymore.

Source: https://gcoding.org/tools/minecraft-generic/commands/playerhealth.php?f=mine52team