My rewards videos not apprearing anymore

hello @madhumita

Through this messages, I welcome you to the king community. 
Currently the King has released a large number of new events & offers, and has shared it through a few groups. Not all events are for everyone. Before any change is implemented a randomly chosen group of players is selected to trial the feature, and based upon how the change is viewed king then decide whether the change is one they want to adopt or not. This feature has been rolled out to different players for a certain amount of time but not everyone will receive this.
If you not received AD that mean you are now not under the testing group.  
however, you can check some troubleshooting. did you using android for this game?

Hello @madhumita
Thank you for your reply.
Tou can check some troubleshooting.
Check your app update here
Update device software If there is a software glitch, you can get rid of it by installing the latest software version. A new version will improve the overall performance of your device and its security and it will also bring bug fixes. If you didn’t enable automatic updates on your device, you can see if there is an update manually