ID: mint_system.website_discount_voucher.view_web_gift_coupan_form_view.barcode_editable
<?xml version="1.0"?>
<data inherit_id="website_discount_voucher.view_web_gift_coupan_form_view" priority="50">
<field name="c_barcode" position="attributes">
<attribute name="readonly">0</attribute>
</field>
</data>
Source: snippets/website_discount_voucher.view_web_gift_coupan_form_view.barcode_editable.xml