I need to display the barcode in sales order window in odoo 10..

I tried this code <barCode code="Code128">123456</barCode> and also this

<img t-att-src="'/report/barcode/?type=%s&amp;value=%s&amp;width=%s&amp;height=%s&amp;humanreadable=1' % ('Code128', '123456', 600, 100)"                                              
                                                style="width:600px;height:75px;"
                                            />

but these two doesn't work for me..

The above code will work in the report, but i need to display it in the Sales Order window..