How to access EJS variable in JavaScript logic?

To access EJS variable in JavaScript logic, we can inject the variable directly into the EJS template.

For instance, we write

<% if (gameState) { %>
<script>
  let clientGameState = <%= gameState %>
</script>
<% } %>

to get the gameState variable with <%= gameState %> and assign that to the clientGameState variable in the script tag.