Why is the size of the story not displayed based on the results of the script?

Question

linux

Good evening!
The size of the history is not displayed based on the results of the script.
Can anyone suggest why?
He writes that he does not find it, in the console echo $HISTSIZE finds

#!/bin/bash

echo "Здравствуйте,$(whoami) ,размер Вашей истории $(HISTSIZE) команд."

Answer 1

$(variable) -- wrong
$(command) -- right
${variable} -- right $ { command
} -- wrong
set -o history