AdMob Ads in App

Hey all, I needed some help as I’m trying to use AdMob ads to show video ads on my app and I got it working fine but I’ve used “AdMobFreeRewardVideo” and I don’t have any reward to give as it’s not a game app that I will give an extra life as a reward for watching the video or so… and if the user cancels the ad in between then it shows a popup saying you’ll not get the reward if you cancel the ad.
So how can I remove that popup and reward keywords I just want to show video ads only.