How can I add the image to header column in using wijmo grid

It would be easier and faster if you post these in grapecity forum, or atleast look there.

Based on reply to this query: Row header icon change in Edit mode of Wijmo5 Flex Grid | General Discussion | Wijmo 5 | GrapeCity Forums[^], it seems you can define an ineer html for header which can contain an image.

Seems following should workout, example:

initialized(flex: wijmo.grid.FlexGrid, args) {       
    flex.itemFormatter = function (panel, r, c, cell) {
        var editRange = panel.grid.editRange;
        if (panel.cellType == wijmo.grid.CellType.RowHeader) {                
                cell.innerHTML = "<img src='resources/collapsed.png' alt='image'/>";
                cell.innerText = "";
            }
        }
    }
}

I have not worked or I know of it, you need to try for such specific third party related queries and issues.