Tracking Pixels are a cookie-based solution, which do not rely on the click id being passed in an offer URL. The click id value is stored in the initial cookie logged for that visitor, so conversion tracking will still work, even if the parameter was not passed to an offer. Tracking pixels are always placed after the conversion actually takes place.
To access Conversion Tracking Pixel, open the Settings Menu by clicking the gear icon on the top left of your window from anywhere inside ClickFlare, and then selecting Tracking URLs.
You can use any of the supported tracking pixels (as seen in the image above). Copy the pixel and paste it on the "Thank you page", where the conversion happens (or any other specific place).