How to get Order Attribures in Backend > Order Details > Overview

Dear all,

I have a problem when extend Backend Order Overview.

When the customer creates order I write some custom data for the order in s_order_attributes table. Later I want to read this data in Backend > Order Overview and add or not few buttons in Overview tab.

I extend the overview.js without problem, but can not undestand how to access order attributes. It looks like I can not get it from overview.js. Before the Oder detail window opens I saw the request for the data:

my-site/backend/AttributeData/list?_dc=1558508314332&table=s_order_attributes&page=1&start=0&limit=20

and saw the respons containing the data, but I can not find where this call was created.

The other thing I tried is to create my own Ajax request and get it. So I get the data, but then can not understand how to insert my html code in the Overview tab.

Can you help me - tell me wich way is right way, and to do what I want?

Best regards!