Uploader with custom extention file restriction

Webix JS
1

Hello webix team,
How to get file dialog with custom extension i.e. .xls,.txt only .
In html we have accept attribute for this file restriction.

how we can implement this with webix?

2

snippet : https://snippet.webix.com/uz54anmu

3

https://docs.webix.com/api__ui.uploader_accept_config.html