Keep conversion tracking of cross domain - GTM

Does anyone know if (and how) it is possible to keep conversions of a cross domain?

My checkout is at example.com, but I have adwords landing pages on my example.nl and example.com domain. I want to optimise the adword campaign of my example.nl domain but I don't know how to keep track of the conversions.

Using GTM

Thanks!

The conversions are tracked back to your keyword(s) in Adwords, from the page you have your tracking pixel (Checkout conversion at example.com). The middle/landing pages, and their domains do not effect this process. I have many different landing page domains, that all funnel to one "thank you" page on a single domain that contains the final tracking pixel.

Awesome, simple. Thanks!