How to make a preview field to reload on another text field change?

I have a custom slug field in an object.
When a user fills title, I need the slug fields to be filled automatically based on the title.

Something like it’s done a Document

I tried preview/iframe field, but it demands manual reload.
I tries calculated field, but it’s demands object reload.

I suspect I can reuse the Document approach. But how?

Please, give me a hint. Thanks.