Open the HTML for the page you wish to track as a conversion on your website. E.g Thank you for your order, or homepage if they are coming from an external source.
Between the body tags (<body></body>) of the page, paste your conversion tracking pixel. You will have got this after you set up the conversion in the Nudge Dashboard or been sent it by you Nudge account manager. It should look something like this. <img src=//c.ndg.io/c/xxxxxxxxxxxxxxxxxx.gif" height="1" width="1" style="display:none" />