Great question — answering as the UphillTech team:
You could use Google Analytics' real time feature and check if the conversion works in real time. As @GeoffAtkins mentioned, you'd need to click on a Google Ad --> then submit a form successfully on the website from that click (while in Google Analytics you can look at it in real time and see the click and the source of traffic medium as CPC). I am guessing there's a /thank-you type of page when form is submitted successfully that you can see you landed on and traffic source remained CPC.
Full answer by Lernisios: https://webmasters.stackexchange.com/a/138653 (CC BY-SA 4.0).
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