Hi,
In 1.15.2 in our custom entity class you had a function called registerAttributes where you could set MAX_HEALTH, MOVEMENT_SPEED, ATTACK_DAMAGE, etc. Like this:
@Override
protected void registerAttributes()
{
super.registerAttributes();
this.getAttribute(SharedMonsterAttributes.MAX_HEALTH).setBaseValue(20.0D);
this.getAttribute(SharedMonsterAttributes.MOVEMENT_SPEED).setBaseValue(0.5D);
this.getAttributes().registerAttribute(S