Custom Locale not working

What?

I want to create custom Locale.

The problem? Most of labels without any update:
https://snippet.dhtmlx.com/dx73zhwe

No docs example for this.

Hello,
You need to connect the “dateFnsLocale”:

<script src="https://cdn.jsdelivr.net/npm/date-fns@3.6.0/locale/he/cdn.js"></script>

And then set up your locale:

const he = {
    dateFnsLocale: window.dateFns.locale.he,
    scheduler: { // translations of the Event Calendar labels
        //...
    },
    calendar: { // translations and settings of the calendar
        //...
    },
};

Please see an example: DHTMLX Snippet Tool