How can I prevent header and row number from being focused?

[yermek-coder]

I want to make so user can only focus and select actual data in the table, please help!

[ota-meshi]

This grid is implemented so that it can focus on all cells including the header.
The ability to focus on the header also allows you to add actions such as copying the header text, click action, or etc.
You cannot opt out of the focus of the header cell.