Rails 7 Import Maps: how to use new window.variable in .html view?

Question

application.js:

import func from 'my_func';
let value = func();
console.log(value) // 123

window.window_value = value;

Then I try to use it in my .html.slim view:

h1 It's my templates

javascript:
  console.log(window.window_value); // undefined
  console.log(window_value); // undefined error

Then in console:

window.window_value; // 123
window_value; // 123   

That means code from my view is faster then code from application.js.