This tutorial will presume you have already connected your website to Google Tag Manager.
Log in to your Tag Manager account and go to Workspace. Click on Tags. Create a New tag.
Click on "Tag Configuration" and choose "Custom HTML" as the tag type.
Log in to your iRefer account and navigate to your campaign by clicking on the "
" button in your Dashboard.
In the left navigation, click on the "Installation" button, then "Custom website" as shown in this screenshot.
Copy the line of code as shown above and paste into the "Custom HTML" field in Tag Manager as shown below.
Click on "Triggering" and choose "All Pages." Click the "Save" button top right of the page.
To make your tag live, click the "Submit" button top right of the page.