...
We do not recommend to execute the conversion tag in the browser, independent if you use a tag management system or not. We would expect a significant loss of data (15-25%) using a browser-side setup, and even more if you use a tag manger, since they are well known to ad-blocking software and browsers and can be easily blocked.
Execute the conversion tag server-side (and hence bypassing the browser). You may use a server-side tagging solution (like server-side Google Tag Manager) if you execute the JavaScript part (ga.js) on a first-party domain (recommended by Google).
Read more: Configuring and implementing tracking tags server-to-server (S2S)
Track cookieless using click IDs (iclid)
...
With every redirect click, Ingenious transmits a click id as parameter iclid (Ingenious Click Id). This iclid(s) should be stored on the advertiser-side in the user-session (in a first party cookie, or attached to the sale/order) and transmitted in the conversion tag. Note that an order might have multiple click IDs assigned, because the user might have several independent interactions before the conversion.
...